超级化激活环核苷酸门控（HCN）通道及其亚型在大鼠膀胱兴奋性调控中的作用初探
|
摘要
背景与研究目的：
膀胱兴奋性的改变在多种排尿功能障碍性疾病的发生发展中起着不可忽视的作用。而导致膀胱兴奋性变化的原因很多，如梗阻、炎症、神经病变等，其中以膀胱部分出口梗阻(partial bladder outlet obstruction，PBOO)和其他中枢及外周神经系统病变多见，是导致尿频、尿急、甚至急迫性尿失禁等膀胱过度活动(overactive bladder，OAB)症候群的重要原因。目前对OAB的发病机制尚未完全阐明，临床针对其治疗主要还是以胆碱能神经受体作为主要靶点，辅助应用肾上腺素能受体阻断剂及钙离子通道阻断剂配合治疗。面对部分由非神经因素造成的特发性OAB患者，该治疗效果欠佳。毫无疑问，对膀胱兴奋性的研究成为当前领域的研究热点。
膀胱主要受神经系统的支配，同时，也具有不依赖神经因素的自发性兴奋性。对各种病理状态下的膀胱兴奋性改变的认识，目前学术界存在着两派学说，即以WC deGroat为代表“神经源性学说”和以AF Brading为代表的“肌源性学说”。前者长期以来强调，膀胱的活动是由中枢及外周神经系统控制的，其发生的一系列兴奋性及收缩性的改变均与神经有着密切联系，主要表现在传入传出神经或神经元的变化、各种神经递质的产生和分泌变化以及各种神经受体数量和功能的变化。但后者认为，除开神经的影响因素，逼尿肌本身兴奋性的变化、逼尿肌细胞之间通讯的改变、各种化学和牵张感受细胞的生理功能变化也参与了膀胱兴奋性的调控。目前，“肌源性”学说作为传统“神经源性”学说的重要补充已逐步被学术界认可，在膀胱兴奋性调控领域的影响日渐增加。
膀胱卡哈尔间质细胞(interstitial cell of Cajal，ICC)的发现，使膀胱来源的因素在膀胱兴奋性调控中的作用逐渐受到重视。膀胱ICCs是2002年首先被英国学者McCloskey在豚鼠中发现的一类与胃肠道起搏细胞ICC类似的特殊间质细胞。膀胱ICCs的具体生理作用目前还有争议，从最初的参与膀胱活动的起搏，到神经信号的整合及传递，以及作为感受器将各种刺激上传，都进行了深入的研究。而离子通道，这种参与细胞兴奋性调控最直接的组件，在膀胱中，尤其是膀胱平滑肌(bladder smoothmuscle cells, BSMCs)和ICCs上，被作为中心环节进行了诸多研究，也是目前膀胱兴奋性的研究热点。
膀胱ICCs维持其功能及发挥作用依赖于细胞膜及胞内分布的各种离子通道。目前在膀胱ICCs上已经发现的通道非常多，与细胞兴奋性和收缩性直接相关的包括电压门控钙通道、大电导钙激活钾通道、ATP依赖的钾通道、快速激活的钠通道、氯离子通道等。而在自发节律产生中占有绝对关键地位的超极化激活环核苷酸门控阳离子(hyperpolarization-activated cyclic nucleotide-gated, HCN)通道在可兴奋细胞中的研究才刚刚起步，只是在神经元及窦房结中得到了深入探讨，而其他组织中的各种重要可兴奋细胞上的研究还只停留在初级阶段。HCN通道对于细胞兴奋性的维持和调节可能具有重要且深远的意义。
HCN通道是最初在心脏和神经元中发现的一类具有特殊生理特性的离子通道，他和其他众多在去极化阶段激活的通道相反，在超极化阶段才能激活，并引发阳离子内流，HCN通道具有普通离子通道不具备的一些特殊的特性，比如复杂的双门控调节、混合离子通透性、微弱的单通道电导等，而其产生的Ih电流呈电压依赖性，除了被普遍认为是起搏活动必须的“起搏电流”外，还具有稳定细胞膜电位、参与可兴奋细胞自律性的调节、调节神经递质释放、参与各种感觉、视觉、听觉信号整合等基础生理功能。HCN通道是否在胃肠道ICCs中参与其慢波电位的形成也是学者们最为关注的方面，在窦房结以外的细胞和组织中，HCN通道产生的Ih电流能否成为pacemaker的主要构成成分都是亟待解决的问题。
膀胱兴奋性改变在膀胱病理状态下导致的一系列临床症状有直接的联系，膀胱ICCs作为新近发现的一类特殊间质细胞，在泌尿系统中具有多种生理功能，且与膀胱兴奋性调控密切相关。而同样参与多种生理功能调控的HCN通道及其亚型是否参与膀胱兴奋性调控是一个非常有趣而且大胆的设想，目前世界上还没有针对这个方面进行研究的团队。首次将膀胱ICCs上的HCN通道作为膀胱兴奋性研究的切入点具有一定的前瞻性，可为膀胱兴奋性调控研究提供新的思路，并为临床治疗排尿功能障碍性疾病提供了潜在的作用靶点，丰富泌尿系统病理生理的理论基础。
基于膀胱兴奋性的调节，本研究通过分子生物学和形态学方法对HCN通道及其亚型在膀胱ICCs中的表达及分布进行观察，通过功能学手段对HCN通道参与ICCs兴奋性调控和膀胱兴奋收缩的机制进行了初步探索，并对膀胱ICCs上的HCN通道的基本生理特性进行了初步研究。
材料及方法：
本研究采用2-3月龄大鼠作为主要研究对象，首先利用RT-PCR和Western blotting技术对正常膀胱组织中HCN通道1-4四个亚型的表达进行研究；然后通过免疫荧光技术阐述该通道四个亚型在膀胱中的具体分布情况；通过金属离子荧光探针负载技术观察培养的ICCs胞内钙离子和钾离子浓度在HCN通道阻断剂作用下的变换，以及对该通道阻断剂对离体膀胱逼尿肌肌条牵张诱发的节律性收缩的影响，从而了解该通道在膀胱兴奋收缩中的作用；最后利用膜片钳技术对急性分离的ICCs上的HCN通道电流进行检测，并记录特异性阻断剂下该电流的变化情况。
结果：
1. RT-PCR发现膀胱组织中HCN1-4四个亚型的mRNA均有表达，与心脏和小肠类似；WB检测发现膀胱组织中HCN1-4四个亚型的蛋白均有表达，利用灰度值进行半定量分析发现HCN1亚型表达比例最高。
2.激光共聚焦显微镜观察正常大鼠膀胱中HCN阳性和c-kit阳性的细胞有共存现象，与myosin阳性的细胞无共存现象。
3.膀胱ICCs中表达的HCN亚型以HCN1、HCN2、HCN4为主，并未检测到HCN3亚型表达。
4. HCN通道阻断剂ZD7288能使静息状态下的膀胱ICCs胞内钙一过性不明显上升，但能显著降低高钾诱发的胞内钙离子浓度升高。
5. ZD7288能显著降低静息状态下的膀胱ICCs胞内钾离子浓度，但拮抗高钾诱发的胞内钾离子浓度上升效果不明显。
6. ZD7288可显著降低正常逼尿肌肌条的自发性收缩幅度，但小幅度上调了收缩频率，且ICCs特异性拮抗剂Glivec作用后收缩现象无明显变化。
7.成功获得急性酶分离的大鼠膀胱ICCs，并在该细胞上记录到典型的Ih电流轨迹，ZD7288作用10min后效果稳定，能显著降低该电流强度。
结论：
1.正常大鼠膀胱中HCN通道主要表达在膀胱ICCs上，亚型以HCN1、HCN2、HCN4为主，未发现HCN3亚型表达。而平滑肌上则没有HCN通道表达。
2. HCN通道与膀胱ICCs的兴奋密切相关，阻断该通道能降低兴奋时胞内的钙离子浓度。且该通道参与了稳定膀胱ICCs静息状态下膜电位的作用，ICCs兴奋时该通道阻断剂使胞内钾离子浓度下降不明显说明细胞K+内流并不是主要依靠HCN通道完成。
3. HCN通道可能通过膀胱ICCs影响膀胱肌肉的兴奋性及收缩性，而非膀胱逼尿肌，且主要通过Ih电流参与各种功能的调控。
Background and Objective：
Change of bladder excitation was the most important reason for the generation anddevelopment of micturational dysfunctions. Obstruction, imflammations and nervousdiseases were candidate for the alteration of excitability of urinary bladder. Overactivebladder(OAB) secondary to the partial bladder outlet obstruction (PBOO) and otherdiseases of central and peripheral nervous system is one of the most common micturationaldysfunction in urology which was represented by urinary frequency, urinary urgency, andeven stress urinary incontinence. The exact pathophysiologic mechanism is unknown untilnow. Cholinergic receptors were chose as pharmacol target in treatment in the clinic aspectstoward OAB. Anti-adrenonergic receptor agents and calcium channel blocker are used alsoas assistance and show effective results. However, it’s hard to solve the idiopathic OABcaused by non-neurogenic factors and the treatment for it is not effective enough. There isno doubt that researches on bladder excitability will become a hot spot in this field.
Urinary bladder is innervatied by nervous system, while self-excitation without thecontrol of nerve is also a special function of vesicles. Two theories were wide-spreaded inthe world on the changes of bladder excitation in several pathologic statuses.“Neurogenictheory” proposed by W.C. de Groat emphasized that all activities of bladder were controlledby central and peripheral nervous system. Series of excitatory and contractile changes wereclosely associatied with nerves. Disturbance of afferent and efferent nerve fibers,neurotransmitter secretion problems and neuroreceptor alterations were candidate for it.Nevertheless,“myogenic theory” proposed by A.F. Brading indicated that changes ofdetrusor excitation, cell-to-cell communication and the physiological functions of chemicaland mechanical stretch reception cells participate in the regulation of bladder excitation. “Myogenic” theories were widely accepted by scientists all over the world as a bestcomplementary for “neurogenic” theories in the field of bladder excitation regulations andget more and more concerns.
“Myogenic/cystogenic” factors in the controlling of bladder excitation gain much moreinterests right after the charactization of interstitial cells of Cajal in bladder which was firstfound in guinea-pig bladder by a British scientists McCloskey. However, the physiologicalfunctions of bladder ICCs are still controversial and gain many attentions of researchers.From the initiation of bladder activity, integration and transmission of neurosigmals toupload the informations as stimulation receptors, there are still a long way to go. Ionchannels, which were considered as direct controlling module in bladder, especially onbladder smooth muscle cells and interstitial cells of Cajal, were investigated by severalresearch groups as a vital component.
Maintain and operation of functions in bladder ICCs rely on the various ion channelslocated on the cellular membrane and intracellular aspects. Lots of ion channels have beenidentified in bladder ICCs, including voltage-gated calcium channels, BK channel,ATP-sensitive potassium channel, rapid sodium channel and chloride channels which wereassociated with cellular excitation. Hyperpolarization-activated cyclic nucleoted-gated(HCN) channel, first found in sinoatrial node and neurons, become more and more“popular” to the scientists because it was associated closely with autorhythmicity. Studiesof HCN channels on excitatory cells were just at the beginning stage and most of theapproaches were applied in neurons and sinoatrial node. Experiments on other excitatorycells expected more investigations and may explore some important significance.
HCN channel was a special ion channel firstly found in heart and neurons. Unlike theactivation mode of normal channels which opened in the depolarization period, HCNchannels opened in the hyperpolarization stage and generated an inward cation current. Theunique properties such as complicatied dual-gate mechanism, permeation of admixture ionsand weak single channel conductance were different from most of the other channels. Thecurrent Ih generated by HCN channels was considered to be a pacemaker current inpacemaking activities. In addition, Ih also plays an important role in several basicphysiological functions such as stabilizing the resting membrane potential, regulating theautorhythmicity and controlling the release of neurotransmitters in excitatory cells. Wether Ih current form the slow wave in the gastrointestinal tract is a good and complicatiedquestion.
Generally speaking, excitation changes of bladder have a close connection with seriesof clinical symptons secondary to the bladder diseases. The newly found bladder ICC was aspecial interstitial cell and functions a lot in urinary tract and was considered to be a keyfactor in modulation of bladder excitation. It is interesting that we hypothesis themulti-functional HCN channels was located on multi-functional ICCs in bladder, and selectHCN channel and its subtypes as a breakpoint to understand the bladder excitation. So far,few studies have focused on the HCN channels located in the urinary bladder, especiallytheir biophysical properties and their role in cell excitation. Researches about HCNchannels on bladder ICCs may reveal a new pathophysiological theory in urology andprovide new ideas on excitation investigations.
Materials and Methods：
Female Sprague–Dawley rats (weighing180-220g) were used in studies. RT-PCR andWestern blotting were taken to investigate the transcripts and protein expression of HCN1-4.Double labeled immunofluorescent study was performed then to identify the location ofHCN channel and its subtypes in bladder. Change of cytoplasmic Ca2+and K+combinedwith fluorescent molecular probes was observed to understand the effects of HCN channelblocker on ICCs. Bladder smooth muscle was studied as isolated strips and specific channelinhibitor ZD7288was then applied to characterized the effect of HCN channel and itsmechanism in regulating bladder contraction. Last but no the least, patch clamp techniquewas used in enzymed-dispersed bladder ICCs and Ih current can be recorded in thewhole-cell mode. HCN channel blocker was also applied to explore the changes of thecurrent.
Results and Discussion：
1. We detected mRNA corresponding to all four of the HCN channel subtypes in theurinary bladder of the rat. The heart and intestine were used as positive controls. All HCNchannel isolations protein can be detected in bladder tissue using Western blotting. Relativeexpression level of the HCN channel subtypes showed the expression of HCN1issignificantly higher than that of other subtypes.
2. Within the individual cell bodies, the HCN isoform and kit immunostaining were uniformly present throughout the cytoplasm, but no co-labeling of HCN1-4and smoothmuscle was observed.
3. There was no apparent staining for the HCN3subtype in the interstitial regions.HCN1, HCN2and HCN4were the prominent isolations locatied on bladder ICCs.
4. Specific HCN channel blocker ZD7288raise the concentration of intracellular Ca2+in an inapparent level of bladder ICCs at resting state, but reduced the concentration ofintracellular Ca2+induced by a higher concentration of extracellular K+significantly.
5. Concentration of cytoplasmic potassium can be depressed by ZD7288at restingstate. But ZD7288reduce the concentration of K+induced by a higher extracellular K+wasinapparent.
6. The amplitude of the detrusor strips can be reduced by selective HCN channelblocker ZD7288, while contractile frequency was raised by it. Application of Glivec, whichwas a significant ICC inhibitor, makes no difference in contraction followed up withZD7288.
7. Bladder ICCs can be isolated by enzyme and used in electrophysiological studies.Typical Ih current traces were recorded and ZD7288can significantly reduce the currentamplitude.
Conclusion：
1. HCN channel and its subtypes were located on bladder ICCs, neither on BSMCs.HCN3subtype was not expressed in native rat bladder. Other isolations can be found in allregions of urinary bladder.
2. HCN channel was closely associated with cellular excitation of bladder ICCs.Intracellular Ca2+can be reduced by using HCN channel blocker when ICCs were activatedand HCN channel participate in stabilizing resting membrane potentials. Influx ofpotassium was not carried out by HCN channel.
3. HCN channel can affect the excitation and contraction of bladder, presumably viabladder ICCs and the regulation of series cellular functions probably was carried outthrough Ih current.
膀胱兴奋性的改变在多种排尿功能障碍性疾病的发生发展中起着不可忽视的作用。而导致膀胱兴奋性变化的原因很多，如梗阻、炎症、神经病变等，其中以膀胱部分出口梗阻(partial bladder outlet obstruction，PBOO)和其他中枢及外周神经系统病变多见，是导致尿频、尿急、甚至急迫性尿失禁等膀胱过度活动(overactive bladder，OAB)症候群的重要原因。目前对OAB的发病机制尚未完全阐明，临床针对其治疗主要还是以胆碱能神经受体作为主要靶点，辅助应用肾上腺素能受体阻断剂及钙离子通道阻断剂配合治疗。面对部分由非神经因素造成的特发性OAB患者，该治疗效果欠佳。毫无疑问，对膀胱兴奋性的研究成为当前领域的研究热点。
膀胱主要受神经系统的支配，同时，也具有不依赖神经因素的自发性兴奋性。对各种病理状态下的膀胱兴奋性改变的认识，目前学术界存在着两派学说，即以WC deGroat为代表“神经源性学说”和以AF Brading为代表的“肌源性学说”。前者长期以来强调，膀胱的活动是由中枢及外周神经系统控制的，其发生的一系列兴奋性及收缩性的改变均与神经有着密切联系，主要表现在传入传出神经或神经元的变化、各种神经递质的产生和分泌变化以及各种神经受体数量和功能的变化。但后者认为，除开神经的影响因素，逼尿肌本身兴奋性的变化、逼尿肌细胞之间通讯的改变、各种化学和牵张感受细胞的生理功能变化也参与了膀胱兴奋性的调控。目前，“肌源性”学说作为传统“神经源性”学说的重要补充已逐步被学术界认可，在膀胱兴奋性调控领域的影响日渐增加。
膀胱卡哈尔间质细胞(interstitial cell of Cajal，ICC)的发现，使膀胱来源的因素在膀胱兴奋性调控中的作用逐渐受到重视。膀胱ICCs是2002年首先被英国学者McCloskey在豚鼠中发现的一类与胃肠道起搏细胞ICC类似的特殊间质细胞。膀胱ICCs的具体生理作用目前还有争议，从最初的参与膀胱活动的起搏，到神经信号的整合及传递，以及作为感受器将各种刺激上传，都进行了深入的研究。而离子通道，这种参与细胞兴奋性调控最直接的组件，在膀胱中，尤其是膀胱平滑肌(bladder smoothmuscle cells, BSMCs)和ICCs上，被作为中心环节进行了诸多研究，也是目前膀胱兴奋性的研究热点。
膀胱ICCs维持其功能及发挥作用依赖于细胞膜及胞内分布的各种离子通道。目前在膀胱ICCs上已经发现的通道非常多，与细胞兴奋性和收缩性直接相关的包括电压门控钙通道、大电导钙激活钾通道、ATP依赖的钾通道、快速激活的钠通道、氯离子通道等。而在自发节律产生中占有绝对关键地位的超极化激活环核苷酸门控阳离子(hyperpolarization-activated cyclic nucleotide-gated, HCN)通道在可兴奋细胞中的研究才刚刚起步，只是在神经元及窦房结中得到了深入探讨，而其他组织中的各种重要可兴奋细胞上的研究还只停留在初级阶段。HCN通道对于细胞兴奋性的维持和调节可能具有重要且深远的意义。
HCN通道是最初在心脏和神经元中发现的一类具有特殊生理特性的离子通道，他和其他众多在去极化阶段激活的通道相反，在超极化阶段才能激活，并引发阳离子内流，HCN通道具有普通离子通道不具备的一些特殊的特性，比如复杂的双门控调节、混合离子通透性、微弱的单通道电导等，而其产生的Ih电流呈电压依赖性，除了被普遍认为是起搏活动必须的“起搏电流”外，还具有稳定细胞膜电位、参与可兴奋细胞自律性的调节、调节神经递质释放、参与各种感觉、视觉、听觉信号整合等基础生理功能。HCN通道是否在胃肠道ICCs中参与其慢波电位的形成也是学者们最为关注的方面，在窦房结以外的细胞和组织中，HCN通道产生的Ih电流能否成为pacemaker的主要构成成分都是亟待解决的问题。
膀胱兴奋性改变在膀胱病理状态下导致的一系列临床症状有直接的联系，膀胱ICCs作为新近发现的一类特殊间质细胞，在泌尿系统中具有多种生理功能，且与膀胱兴奋性调控密切相关。而同样参与多种生理功能调控的HCN通道及其亚型是否参与膀胱兴奋性调控是一个非常有趣而且大胆的设想，目前世界上还没有针对这个方面进行研究的团队。首次将膀胱ICCs上的HCN通道作为膀胱兴奋性研究的切入点具有一定的前瞻性，可为膀胱兴奋性调控研究提供新的思路，并为临床治疗排尿功能障碍性疾病提供了潜在的作用靶点，丰富泌尿系统病理生理的理论基础。
基于膀胱兴奋性的调节，本研究通过分子生物学和形态学方法对HCN通道及其亚型在膀胱ICCs中的表达及分布进行观察，通过功能学手段对HCN通道参与ICCs兴奋性调控和膀胱兴奋收缩的机制进行了初步探索，并对膀胱ICCs上的HCN通道的基本生理特性进行了初步研究。
材料及方法：
本研究采用2-3月龄大鼠作为主要研究对象，首先利用RT-PCR和Western blotting技术对正常膀胱组织中HCN通道1-4四个亚型的表达进行研究；然后通过免疫荧光技术阐述该通道四个亚型在膀胱中的具体分布情况；通过金属离子荧光探针负载技术观察培养的ICCs胞内钙离子和钾离子浓度在HCN通道阻断剂作用下的变换，以及对该通道阻断剂对离体膀胱逼尿肌肌条牵张诱发的节律性收缩的影响，从而了解该通道在膀胱兴奋收缩中的作用；最后利用膜片钳技术对急性分离的ICCs上的HCN通道电流进行检测，并记录特异性阻断剂下该电流的变化情况。
结果：
1. RT-PCR发现膀胱组织中HCN1-4四个亚型的mRNA均有表达，与心脏和小肠类似；WB检测发现膀胱组织中HCN1-4四个亚型的蛋白均有表达，利用灰度值进行半定量分析发现HCN1亚型表达比例最高。
2.激光共聚焦显微镜观察正常大鼠膀胱中HCN阳性和c-kit阳性的细胞有共存现象，与myosin阳性的细胞无共存现象。
3.膀胱ICCs中表达的HCN亚型以HCN1、HCN2、HCN4为主，并未检测到HCN3亚型表达。
4. HCN通道阻断剂ZD7288能使静息状态下的膀胱ICCs胞内钙一过性不明显上升，但能显著降低高钾诱发的胞内钙离子浓度升高。
5. ZD7288能显著降低静息状态下的膀胱ICCs胞内钾离子浓度，但拮抗高钾诱发的胞内钾离子浓度上升效果不明显。
6. ZD7288可显著降低正常逼尿肌肌条的自发性收缩幅度，但小幅度上调了收缩频率，且ICCs特异性拮抗剂Glivec作用后收缩现象无明显变化。
7.成功获得急性酶分离的大鼠膀胱ICCs，并在该细胞上记录到典型的Ih电流轨迹，ZD7288作用10min后效果稳定，能显著降低该电流强度。
结论：
1.正常大鼠膀胱中HCN通道主要表达在膀胱ICCs上，亚型以HCN1、HCN2、HCN4为主，未发现HCN3亚型表达。而平滑肌上则没有HCN通道表达。
2. HCN通道与膀胱ICCs的兴奋密切相关，阻断该通道能降低兴奋时胞内的钙离子浓度。且该通道参与了稳定膀胱ICCs静息状态下膜电位的作用，ICCs兴奋时该通道阻断剂使胞内钾离子浓度下降不明显说明细胞K+内流并不是主要依靠HCN通道完成。
3. HCN通道可能通过膀胱ICCs影响膀胱肌肉的兴奋性及收缩性，而非膀胱逼尿肌，且主要通过Ih电流参与各种功能的调控。
Background and Objective：
Change of bladder excitation was the most important reason for the generation anddevelopment of micturational dysfunctions. Obstruction, imflammations and nervousdiseases were candidate for the alteration of excitability of urinary bladder. Overactivebladder(OAB) secondary to the partial bladder outlet obstruction (PBOO) and otherdiseases of central and peripheral nervous system is one of the most common micturationaldysfunction in urology which was represented by urinary frequency, urinary urgency, andeven stress urinary incontinence. The exact pathophysiologic mechanism is unknown untilnow. Cholinergic receptors were chose as pharmacol target in treatment in the clinic aspectstoward OAB. Anti-adrenonergic receptor agents and calcium channel blocker are used alsoas assistance and show effective results. However, it’s hard to solve the idiopathic OABcaused by non-neurogenic factors and the treatment for it is not effective enough. There isno doubt that researches on bladder excitability will become a hot spot in this field.
Urinary bladder is innervatied by nervous system, while self-excitation without thecontrol of nerve is also a special function of vesicles. Two theories were wide-spreaded inthe world on the changes of bladder excitation in several pathologic statuses.“Neurogenictheory” proposed by W.C. de Groat emphasized that all activities of bladder were controlledby central and peripheral nervous system. Series of excitatory and contractile changes wereclosely associatied with nerves. Disturbance of afferent and efferent nerve fibers,neurotransmitter secretion problems and neuroreceptor alterations were candidate for it.Nevertheless,“myogenic theory” proposed by A.F. Brading indicated that changes ofdetrusor excitation, cell-to-cell communication and the physiological functions of chemicaland mechanical stretch reception cells participate in the regulation of bladder excitation. “Myogenic” theories were widely accepted by scientists all over the world as a bestcomplementary for “neurogenic” theories in the field of bladder excitation regulations andget more and more concerns.
“Myogenic/cystogenic” factors in the controlling of bladder excitation gain much moreinterests right after the charactization of interstitial cells of Cajal in bladder which was firstfound in guinea-pig bladder by a British scientists McCloskey. However, the physiologicalfunctions of bladder ICCs are still controversial and gain many attentions of researchers.From the initiation of bladder activity, integration and transmission of neurosigmals toupload the informations as stimulation receptors, there are still a long way to go. Ionchannels, which were considered as direct controlling module in bladder, especially onbladder smooth muscle cells and interstitial cells of Cajal, were investigated by severalresearch groups as a vital component.
Maintain and operation of functions in bladder ICCs rely on the various ion channelslocated on the cellular membrane and intracellular aspects. Lots of ion channels have beenidentified in bladder ICCs, including voltage-gated calcium channels, BK channel,ATP-sensitive potassium channel, rapid sodium channel and chloride channels which wereassociated with cellular excitation. Hyperpolarization-activated cyclic nucleoted-gated(HCN) channel, first found in sinoatrial node and neurons, become more and more“popular” to the scientists because it was associated closely with autorhythmicity. Studiesof HCN channels on excitatory cells were just at the beginning stage and most of theapproaches were applied in neurons and sinoatrial node. Experiments on other excitatorycells expected more investigations and may explore some important significance.
HCN channel was a special ion channel firstly found in heart and neurons. Unlike theactivation mode of normal channels which opened in the depolarization period, HCNchannels opened in the hyperpolarization stage and generated an inward cation current. Theunique properties such as complicatied dual-gate mechanism, permeation of admixture ionsand weak single channel conductance were different from most of the other channels. Thecurrent Ih generated by HCN channels was considered to be a pacemaker current inpacemaking activities. In addition, Ih also plays an important role in several basicphysiological functions such as stabilizing the resting membrane potential, regulating theautorhythmicity and controlling the release of neurotransmitters in excitatory cells. Wether Ih current form the slow wave in the gastrointestinal tract is a good and complicatiedquestion.
Generally speaking, excitation changes of bladder have a close connection with seriesof clinical symptons secondary to the bladder diseases. The newly found bladder ICC was aspecial interstitial cell and functions a lot in urinary tract and was considered to be a keyfactor in modulation of bladder excitation. It is interesting that we hypothesis themulti-functional HCN channels was located on multi-functional ICCs in bladder, and selectHCN channel and its subtypes as a breakpoint to understand the bladder excitation. So far,few studies have focused on the HCN channels located in the urinary bladder, especiallytheir biophysical properties and their role in cell excitation. Researches about HCNchannels on bladder ICCs may reveal a new pathophysiological theory in urology andprovide new ideas on excitation investigations.
Materials and Methods：
Female Sprague–Dawley rats (weighing180-220g) were used in studies. RT-PCR andWestern blotting were taken to investigate the transcripts and protein expression of HCN1-4.Double labeled immunofluorescent study was performed then to identify the location ofHCN channel and its subtypes in bladder. Change of cytoplasmic Ca2+and K+combinedwith fluorescent molecular probes was observed to understand the effects of HCN channelblocker on ICCs. Bladder smooth muscle was studied as isolated strips and specific channelinhibitor ZD7288was then applied to characterized the effect of HCN channel and itsmechanism in regulating bladder contraction. Last but no the least, patch clamp techniquewas used in enzymed-dispersed bladder ICCs and Ih current can be recorded in thewhole-cell mode. HCN channel blocker was also applied to explore the changes of thecurrent.
Results and Discussion：
1. We detected mRNA corresponding to all four of the HCN channel subtypes in theurinary bladder of the rat. The heart and intestine were used as positive controls. All HCNchannel isolations protein can be detected in bladder tissue using Western blotting. Relativeexpression level of the HCN channel subtypes showed the expression of HCN1issignificantly higher than that of other subtypes.
2. Within the individual cell bodies, the HCN isoform and kit immunostaining were uniformly present throughout the cytoplasm, but no co-labeling of HCN1-4and smoothmuscle was observed.
3. There was no apparent staining for the HCN3subtype in the interstitial regions.HCN1, HCN2and HCN4were the prominent isolations locatied on bladder ICCs.
4. Specific HCN channel blocker ZD7288raise the concentration of intracellular Ca2+in an inapparent level of bladder ICCs at resting state, but reduced the concentration ofintracellular Ca2+induced by a higher concentration of extracellular K+significantly.
5. Concentration of cytoplasmic potassium can be depressed by ZD7288at restingstate. But ZD7288reduce the concentration of K+induced by a higher extracellular K+wasinapparent.
6. The amplitude of the detrusor strips can be reduced by selective HCN channelblocker ZD7288, while contractile frequency was raised by it. Application of Glivec, whichwas a significant ICC inhibitor, makes no difference in contraction followed up withZD7288.
7. Bladder ICCs can be isolated by enzyme and used in electrophysiological studies.Typical Ih current traces were recorded and ZD7288can significantly reduce the currentamplitude.
Conclusion：
1. HCN channel and its subtypes were located on bladder ICCs, neither on BSMCs.HCN3subtype was not expressed in native rat bladder. Other isolations can be found in allregions of urinary bladder.
2. HCN channel was closely associated with cellular excitation of bladder ICCs.Intracellular Ca2+can be reduced by using HCN channel blocker when ICCs were activatedand HCN channel participate in stabilizing resting membrane potentials. Influx ofpotassium was not carried out by HCN channel.
3. HCN channel can affect the excitation and contraction of bladder, presumably viabladder ICCs and the regulation of series cellular functions probably was carried outthrough Ih current.
引文
1. de Groat WC: A neurologic basis for the overactive bladder. Urology1997,50(6ASuppl):36-52; discussion53-36.
2. Brading AF: A myogenic basis for the overactive bladder. Urology1997,50(6ASuppl):57-67; discussion68-73.
3. Hashitani H, Fukuta H, Takano H, Klemm MF, Suzuki H: Origin and propagation ofspontaneous excitation in smooth muscle of the guinea-pig urinary bladder. J Physiol2001,530(Pt2):273-286.
4. Lang RJ, Hashitani H, Tonta MA, Parkington HC, Suzuki H: Spontaneous electricaland Ca2+signals in typical and atypical smooth muscle cells and interstitial cell ofCajal-like cells of mouse renal pelvis. J Physiol2007,583(Pt3):1049-1068.
5. Guay DR: Tolterodine, a new antimuscarinic drug for treatment of bladder overactivity.Pharmacotherapy1999,19(3):267-280.
6. Meng E, Young JS, Brading AF: Spontaneous activity of mouse detrusor smoothmuscle and the effects of the urothelium. Neurourol Urodyn2008,27(1):79-87.
7. Thuneberg L: One hundred years of interstitial cells of Cajal. Microsc Res Tech1999,47(4):223-238.
8. Hanani M, Freund HR: Interstitial cells of Cajal--their role in pacing and signaltransmission in the digestive system. Acta Physiol Scand2000,170(3):177-190.
9. McCloskey KD, Gurney AM: Kit positive cells in the guinea pig bladder. J Urol2002,168(2):832-836.
10. Popescu LM, Ciontea SM, Cretoiu D, Hinescu ME, Radu E, Ionescu N, Ceausu M,Gherghiceanu M, Braga RI, Vasilescu F et al: Novel type of interstitial cell (Cajal-like)in human fallopian tube. J Cell Mol Med2005,9(2):479-523.
11. Ciontea SM, Radu E, Regalia T, Ceafalan L, Cretoiu D, Gherghiceanu M, Braga RI,Malincenco M, Zagrean L, Hinescu ME et al: C-kit immunopositive interstitial cells(Cajal-type) in human myometrium. J Cell Mol Med2005,9(2):407-420.
12. Popescu LM, Hinescu ME, Ionescu N, Ciontea SM, Cretoiu D, Ardelean C: Interstitialcells of Cajal in pancreas. J Cell Mol Med2005,9(1):169-190.
13. Popescu LM, Andrei F, Hinescu ME: Snapshots of mammary gland interstitial cells:methylene-blue vital staining and c-kit immunopositivity. J Cell Mol Med2005,9(2):476-477.
14.沈文浩,李为兵,熊恩庆,宋波,卢根生,金锡御:胃肠道起搏细胞ICCs在豚鼠泌尿道分布研究.第三军医大学学报2006,28(2):172-173.
15. Wang Y, Fang Q, Lu Y, Song B, Li W, Li L: Effects of mechanical stretch oninterstitial cells of Cajal in guinea pig bladder. J Surg Res2010,164(1):e213-219.
16. Solari V, Piotrowska AP, Puri P: Altered expression of interstitial cells of Cajal incongenital ureteropelvic junction obstruction. J Urol2003,170(6Pt1):2420-2422.
17. Schwentner C, Oswald J, Lunacek A, Fritsch H, Deibl M, Bartsch G, Radmayr C: Lossof interstitial cells of Cajal and gap junction protein connexin43at the vesicoureteraljunction in children with vesicoureteral reflux. J Urol2005,174(5):1981-1986.
18. Kubota Y, Hashitani H, Shirasawa N, Kojima Y, Sasaki S, Mabuchi Y, Soji T, SuzukiH, Kohri K: Altered distribution of interstitial cells in the guinea pig bladder followingbladder outlet obstruction. Neurourol Urodyn2008,27(4):330-340.
19. McCloskey KD, Anderson UA, Davidson RA, Bayguinov YR, Sanders KM, Ward SM:Comparison of mechanical and electrical activity and interstitial cells of Cajal inurinary bladders from wild-type and W/Wv mice. Br J Pharmacol2009,156(2):273-283.
20. Davidson RA, McCloskey KD: Morphology and localization of interstitial cells in theguinea pig bladder: structural relationships with smooth muscle and neurons. J Urol2005,173(4):1385-1390.
21. El-Kholy W, MacDonald PE, Fox JM, Bhattacharjee A, Xue T, Gao X, Zhang Y,Stieber J, Li RA, Tsushima RG et al: Hyperpolarization-activated cyclicnucleotide-gated channels in pancreatic beta-cells. Mol Endocrinol2007,21(3):753-764.
22. Seifert R, Scholten A, Gauss R, Mincheva A, Lichter P, Kaupp UB: Molecularcharacterization of a slowly gating human hyperpolarization-activated channelpredominantly expressed in thalamus, heart, and testis. Proc Natl Acad Sci U S A1999,96(16):9391-9396.
23. Benham CD, Bolton TB, Denbigh JS, Lang RJ: Inward rectification in freshly isolatedsingle smooth muscle cells of the rabbit jejunum. J Physiol1987,383:461-476.
24. Green ME, Edwards G, Kirkup AJ, Miller M, Weston AH: Pharmacologicalcharacterization of the inwardly-rectifying current in the smooth muscle cells of the ratbladder. Br J Pharmacol1996,119(8):1509-1518.
25. Xiao J, Nguyen TV, Ngui K, Strijbos PJ, Selmer IS, Neylon CB, Furness JB:Molecular and functional analysis of hyperpolarisation-activated nucleotide-gated(HCN) channels in the enteric nervous system. Neuroscience2004,129(3):603-614.
26. Biel M, Wahl-Schott C, Michalakis S, Zong X: Hyperpolarization-activated cationchannels: from genes to function. Physiol Rev2009,89(3):847-885.
27. Hashitani H, Yanai Y, Suzuki H: Role of interstitial cells and gap junctions in thetransmission of spontaneous Ca2+signals in detrusor smooth muscles of theguinea-pig urinary bladder. J Physiol2004,559(Pt2):567-581.
28. Sui GP, Rothery S, Dupont E, Fry CH, Severs NJ: Gap junctions and connexinexpression in human suburothelial interstitial cells. BJU Int2002,90(1):118-129.
29. Anderson UA, Carson C, McCloskey KD: KCNQ currents and their contribution toresting membrane potential and the excitability of interstitial cells of Cajal from theguinea pig bladder. J Urol2009,182(1):330-336.
30. Johnston L, Carson C, Lyons AD, Davidson RA, McCloskey KD: Cholinergic-inducedCa2+signaling in interstitial cells of Cajal from the guinea pig bladder. Am J PhysiolRenal Physiol2008,294(3):F645-655.
31. Shafik A, El-Sibai O, Shafik AA, Shafik I: Identification of interstitial cells of Cajal inhuman urinary bladder: concept of vesical pacemaker. Urology2004,64(4):809-813.
32.方强,杨景,潘进洪,封建立,李为兵,王永权,丁励蠡,宋波: P2X嘌呤受体在大鼠膀胱ICCs细胞中的表达.第三军医大学学报2008,30(7):564-566.
33.贾卓敏,张永革,方强,等:胆碱能激动剂卡巴可对大鼠膀胱ICC样细胞内钙流的影响.临床泌尿外科杂志2009,24(5):393-395.
34. Faussone-Pellegrini MS, Thuneberg L: Guide to the identification of interstitial cellsof Cajal. Microsc Res Tech1999,47(4):248-266.
35. Thuneberg L, Peters S: Toward a concept of stretch-coupling in smooth muscle. I.Anatomy of intestinal segmentation and sleeve contractions. Anat Rec2001,262(1):110-124.
36. Johnston L, Woolsey S, Cunningham RM, O'Kane H, Duggan B, Keane P, McCloskeyKD: Morphological expression of KIT positive interstitial cells of Cajal in humanbladder. J Urol2010,184(1):370-377.
37. Pezzone MA, Watkins SC, Alber SM, King WE, de Groat WC, Chancellor MB, FraserMO: Identification of c-kit-positive cells in the mouse ureter: the interstitial cells ofCajal of the urinary tract. Am J Physiol Renal Physiol2003,284(5):F925-929.
38. Noma A, Irisawa H: Membrane currents in the rabbit sinoatrial node cell as studied bythe double microelectrode method. Pflugers Arch1976,364(1):45-52.
39. Nolan MF, Malleret G, Lee KH, Gibbs E, Dudman JT, Santoro B, Yin D, ThompsonRF, Siegelbaum SA, Kandel ER et al: The hyperpolarization-activated HCN1channelis important for motor learning and neuronal integration by cerebellar Purkinje cells.Cell2003,115(5):551-564.
40. Ludwig A, Budde T, Stieber J, Moosmang S, Wahl C, Holthoff K, Langebartels A,Wotjak C, Munsch T, Zong X et al: Absence epilepsy and sinus dysrhythmia in micelacking the pacemaker channel HCN2. EMBO J2003,22(2):216-224.
41. Moosmang S, Biel M, Hofmann F, Ludwig A: Differential distribution of fourhyperpolarization-activated cation channels in mouse brain. Biol Chem1999,380(7-8):975-980.
42. Notomi T, Shigemoto R: Immunohistochemical localization of Ih channel subunits,HCN1-4, in the rat brain. J Comp Neurol2004,471(3):241-276.
43. Stieber J, Hofmann F, Ludwig A: Pacemaker channels and sinus node arrhythmia.Trends Cardiovasc Med2004,14(1):23-28.
44.熊承杰,梅峰,韩娟,田衍平,江忠勇,周德山: HCN2阳性细胞在小鼠胃肠道肌间神经丛内的分布.第三军医大学学报2010,32(5):409-413.
45. Barajas-Lopez C, Berezin I, Daniel EE, Huizinga JD: Pacemaker activity recorded ininterstitial cells of Cajal of the gastrointestinal tract. Am J Physiol1989,257(4Pt1):C830-835.
46. Lin ZH, Han EM, Lee ES, Kim CW, Kim HK, Kim I, Kim YS: A distinct expressionpattern and point mutation of c-kit in papillary renal cell carcinomas. Mod Pathol2004,17(6):611-616.
47. Oberritter Z, Rolle U, Juhasz Z, Cserni T, Puri P: Altered expression of c-kit-positivecells in the ureterovesical junction after surgically created vesicoureteral reflux.Pediatr Surg Int2009,25(12):1103-1107.
48. Klemm MF, Exintaris B, Lang RJ: Identification of the cells underlying pacemakeractivity in the guinea-pig upper urinary tract. J Physiol1999,519Pt3:867-884.
49. Lyons AD, Gardiner TA, McCloskey KD: Kit-positive interstitial cells in the rabbiturethra: structural relationships with nerves and smooth muscle. BJU Int2007,99(3):687-694.
50. Shafik A, Shafik I, el-Sibai O: Identification of c-kit-positive cells in the humanprostate: the interstitial cells of Cajal. Arch Androl2005,51(5):345-351.
51. Ordog T, Redelman D, Horowitz NN, Sanders KM: Immunomagnetic enrichment ofinterstitial cells of Cajal. Am J Physiol Gastrointest Liver Physiol2004,286(2):G351-360.
52. Liu HN, Ohya S, Furuzono S, Wang J, Imaizumi Y, Nakayama S: Co-contribution ofIP3R and Ca2+influx pathways to pacemaker Ca2+activity in stomach ICC. J BiolRhythms2005,20(1):15-26.
53. Koh SD, Sanders KM, Ward SM: Spontaneous electrical rhythmicity in culturedinterstitial cells of cajal from the murine small intestine. J Physiol1998,513(Pt1):203-213.
54. Nakamura K, Shibata Y: Connexin43expression in network-forming cells at thesubmucosal-muscular border of guinea pig and dog colon. Cells Tissues Organs1999,165(1):16-21.
55. Huizinga JD, Zhu Y, Ye J, Molleman A: High-conductance chloride channels generatepacemaker currents in interstitial cells of Cajal. Gastroenterology2002,123(5):1627-1636.
56. Walker RL, Koh SD, Sergeant GP, Sanders KM, Horowitz B: TRPC4currents haveproperties similar to the pacemaker current in interstitial cells of Cajal. Am J PhysiolCell Physiol2002,283(6):C1637-1645.
57. Lavoie B, Balemba OB, Nelson MT, Ward SM, Mawe GM: Morphological andphysiological evidence for interstitial cell of Cajal-like cells in the guinea piggallbladder. J Physiol2007,579(Pt2):487-501.
58. Torihashi S, Fujimoto T, Trost C, Nakayama S: Calcium oscillation linked topacemaking of interstitial cells of Cajal: requirement of calcium influx and localizationof TRP4in caveolae. J Biol Chem2002,277(21):19191-19197.
59. Johnston L, Sergeant GP, Hollywood MA, Thornbury KD, McHale NG: Calciumoscillations in interstitial cells of the rabbit urethra. J Physiol2005,565(Pt2):449-461.
60. Laskay G, Varhelyi T, Dale RE, Dexter TM: Role of interleukin-3in the regulation ofintracellular K+homeostasis in cultured murine haemopoietic cells. Biochem BiophysRes Commun1995,214(2):348-353.
61. Grieshaber S, Swanson JA, Hackstadt T: Determination of the physical environmentwithin the Chlamydia trachomatis inclusion using ion-selective ratiometric probes.Cell Microbiol2002,4(5):273-283.
62. Andersson B, Janson V, Behnam-Motlagh P, Henriksson R, Grankvist K: Induction ofapoptosis by intracellular potassium ion depletion: using the fluorescent dye PBFI in a96-well plate method in cultured lung cancer cells. Toxicol In Vitro2006,20(6):986-994.
63. Yu X, Duan KL, Shang CF, Yu HG, Zhou Z: Calcium influx throughhyperpolarization-activated cation channels (I(h) channels) contributes toactivity-evoked neuronal secretion. Proc Natl Acad Sci U S A2004,101(4):1051-1056.
64. Yu FH, Catterall WA: The VGL-chanome: a protein superfamily specialized forelectrical signaling and ionic homeostasis. Sci STKE2004,2004(253):re15.
65. Doyle DA, Morais Cabral J, Pfuetzner RA, Kuo A, Gulbis JM, Cohen SL, Chait BT,MacKinnon R: The structure of the potassium channel: molecular basis of K+conduction and selectivity. Science1998,280(5360):69-77.
66. Zhou Y, Morais-Cabral JH, Kaufman A, MacKinnon R: Chemistry of ion coordinationand hydration revealed by a K+channel-Fab complex at2.0A resolution. Nature2001,414(6859):43-48.
67. Shi N, Ye S, Alam A, Chen L, Jiang Y: Atomic structure of a Na+-and K+-conductingchannel. Nature2006,440(7083):570-574.
68. Yang J, Ellinor PT, Sather WA, Zhang JF, Tsien RW: Molecular determinants of Ca2+selectivity and ion permeation in L-type Ca2+channels. Nature1993,366(6451):158-161.
69. Zagotta WN: Membrane biology: permutations of permeability. Nature2006,440(7083):427-429.
70. Azene EM, Xue T, Li RA: Molecular basis of the effect of potassium onheterologously expressed pacemaker (HCN) channels. J Physiol2003,547(Pt2):349-356.
71. Er F, Larbig R, Ludwig A, Biel M, Hofmann F, Beuckelmann DJ, Hoppe UC:Dominant-negative suppression of HCN channels markedly reduces the nativepacemaker current I(f) and undermines spontaneous beating of neonatalcardiomyocytes. Circulation2003,107(3):485-489.
72. Macri V, Proenza C, Agranovich E, Angoli D, Accili EA: Separable gatingmechanisms in a Mammalian pacemaker channel. J Biol Chem2002,277(39):35939-35946.
73. Much B, Wahl-Schott C, Zong X, Schneider A, Baumann L, Moosmang S, Ludwig A,Biel M: Role of subunit heteromerization and N-linked glycosylation in the formationof functional hyperpolarization-activated cyclic nucleotide-gated channels. J BiolChem2003,278(44):43781-43786.
74. Xue T, Marban E, Li RA: Dominant-negative suppression of HCN1-andHCN2-encoded pacemaker currents by an engineered HCN1construct: insights intostructure-function relationships and multimerization. Circ Res2002,90(12):1267-1273.
75. Lang RJ, Takano H, Davidson ME, Suzuki H, Klemm MF: Characterization of thespontaneous electrical and contractile activity of smooth muscle cells in the rat upperurinary tract. J Urol2001,166(1):329-334.
76. Lam M, Shigemasa Y, Exintaris B, Lang RJ, Hashitani H: Spontaneous Ca2+signaling of interstitial cells in the guinea pig prostate. J Urol2011,186(6):2478-2486.
77. Wray S: Smooth muscle intracellular pH: measurement, regulation, and function. Am JPhysiol1988,254(2Pt1):C213-225.
78. DiFrancesco D: Characterization of single pacemaker channels in cardiac sino-atrialnode cells. Nature1986,324(6096):470-473.
79. Kole MH, Hallermann S, Stuart GJ: Single Ih channels in pyramidal neuron dendrites:properties, distribution, and impact on action potential output. J Neurosci2006,26(6):1677-1687.
80. Michels G, Er F, Khan I, Sudkamp M, Herzig S, Hoppe UC: Single-channel propertiessupport a potential contribution of hyperpolarization-activated cyclic nucleotide-gatedchannels and If to cardiac arrhythmias. Circulation2005,111(4):399-404.
81. Simeone TA, Rho JM, Baram TZ: Single channel properties of hyperpolarization-activated cation currents in acutely dissociated rat hippocampal neurones. J Physiol2005,568(Pt2):371-380.
82. Michels G, Er F, Khan IF, Endres-Becker J, Brandt MC, Gassanov N, Johns DC,Hoppe UC: K+channel regulator KCR1suppresses heart rhythm by modulating thepacemaker current If. PLoS One2008,3(1):e1511.
83. Sakmann B, Neher E: Patch clamp techniques for studying ionic channels in excitablemembranes. Annu Rev Physiol1984,46:455-472.
84. Tang G, Wang R: Differential expression of KV and KCa channels in vascular smoothmuscle cells during1-day culture. Pflugers Arch2001,442(1):124-135.
85. Kuga T, Kobayashi S, Hirakawa Y, Kanaide H, Takeshita A: Cell cycle--dependentexpression of L-and T-type Ca2+currents in rat aortic smooth muscle cells in primaryculture. Circ Res1996,79(1):14-19.
86. Ma FH, Higashira H, Ukai Y, Hanai T, Kiwamoto H, Park YC, Kurita T: A newenzymic method for the isolation and culture of human bladder body smooth musclecells. Neurourol Urodyn2002,21(1):71-79.
87. Schot R, van Asselt E, van Mastrigt R: A method for isolating smooth muscle cellsfrom pig urinary bladder with low concentrations of collagenase and papain: therelation between calcium concentration and isolated cell length. Urol Res1993,21(1):49-53.
88. Klockner U, Isenberg G: Action potentials and net membrane currents of isolatedsmooth muscle cells (urinary bladder of the guinea-pig). Pflugers Arch1985,405(4):329-339.
89. Bean BP, Sturek M, Puga A, Hermsmeyer K: Calcium channels in muscle cellsisolated from rat mesenteric arteries: modulation by dihydropyridine drugs. Circ Res1986,59(2):229-235.
90. Chen J, Piper DR, Sanguinetti MC: Voltage sensing and activation gating of HCNpacemaker channels. Trends Cardiovasc Med2002,12(1):42-45.
91. Biel M, Schneider A, Wahl C: Cardiac HCN channels: structure, function, andmodulation. Trends Cardiovasc Med2002,12(5):206-212.
92. Fernandez-Velasco M, Goren N, Benito G, Blanco-Rivero J, Bosca L, Delgado C:Regional distribution of hyperpolarization-activated current (If) andhyperpolarization-activated cyclic nucleotide-gated channel mRNA expression inventricular cells from control and hypertrophied rat hearts. J Physiol2003,553(Pt2):395-405.
93. Chen K, Aradi I, Thon N, Eghbal-Ahmadi M, Baram TZ, Soltesz I: Persistentlymodified h-channels after complex febrile seizures convert the seizure-inducedenhancement of inhibition to hyperexcitability. Nat Med2001,7(3):331-337.
94. Gold MS: Spinal nerve ligation: what to blame for the pain and why. Pain2000,84(2-3):117-120.
[1] Brown HF, Giles W, Noble SJ. Membrane currents underlying activity in frog sinusvenosus. J Physiol271:783–816,1977.
[2] Halliwell JV, Adams PR. Voltage-clamp analysis of muscarinic excitation inhippocampal neurons. Brain Res250:71–92,1982.
[3] Maccaferri G, Mangoni M, Lazzari A, DiFrancesco D. Properties of thehyperpolarization-activated current in rat hippocampal CA1pyramidal cells. JNeurophysiol69:2129–2136,1993.
[4] DiFrancesco D. Pacemaker mechanisms in cardiac tissue. Annu Rev Physiol55:455–472,1993
[5] Brown HF, DiFrancesco D, Noble SJ. How does adrenaline accelerate the heart? Nature280:235–236,1979.
[6] DiFrancesco D, Ducouret P, Robinson RB. Muscarinic modulation of cardiac rate atlow acetylcholine concentrations. Science243:669–671,1989.
[7] DiFrancesco D. A new interpretation of the pace-maker current in calf Purkinje fibres. JPhysiol314:359–376,1981.
[8] Harzheim D, Pfeiffer KH, Fabritz L, Kremmer E, Buch T, Waisman A, Kirchhof P,Kaupp UB, Seifert R. Cardiac pacemaker function of HCN4channels in mice isconfined to embryonic development and requires cyclic AMP. EMBO J27:692–703,2008.
[9] Herrmann S, Stieber J, Stockl G, Hofmann F, Ludwig A. HCN4provides a“depolarization reserve” and is not required for heart rate acceleration in mice. EMBO J26:4423–4432,2007.
[10] Ludwig A, Budde T, Stieber J, Moosmang S, Wahl C, Holthoff K, Langebartels A,Wotjak C, Munsch T, Zong X, Feil S, Feil R, Lancel M, Chien KR, Konnerth A, PapeHC, Biel M, Hofmann F. Absence epilepsy and sinus dysrhythmia in mice lacking thepacemaker channel HCN2. EMBO J22:216–224,2003.
[11] Stieber J, Herrmann S, Feil S, Loster J, Feil R, Biel M, Hofmann F, Ludwig A. Thehyperpolarization-activated channel HCN4is required for the generation of pacemakeraction potentials in the embryonic heart. Proc Natl Acad Sci USA100:15235–15240,2003.
[12] McCormick DA, Huguenard JR. A model of the electrophysiological properties ofthalamocortical relay neurons. J Neurophysiol68:1384–1400,1992.
[13] Day M, Carr DB, Ulrich S, Ilijic E, Tkatch T, Surmeier DJ. Dendritic excitability ofmouse frontal cortex pyramidal neurons is shaped by the interaction among HCN, Kir2,and Kleak channels. J Neurosci25:8776–8787,2005.
[14] Pape HC. Queer current and pacemaker: the hyperpolarizationactivated cation currentin neurons. Annu Rev Physiol58:299–327,1996.
[15] Magee JC. Dendritic hyperpolarization-activated currents modify the integrativeproperties of hippocampal CA1pyramidal neurons. J Neurosci18:7613–7624,1998.
[16] Beaumont V, Zhong N, Froemke RC, Ball RW, Zucker RS. Temporal synaptic taggingby I(h) activation and actin: involvement in long-term facilitation and cAMP-inducedsynaptic enhancement. Neuron33:601–613,2002.
[17] Beaumont V, Zucker RS. Enhancement of synaptic transmission by cyclic AMPmodulation of presynaptic Ih channels. Nat Neurosci3:133–141,2000
[18] Demontis GC, Cervetto L. Vision: how to catch fast signals with slow detectors. NewsPhysiol Sci17:110–114,2002.
[19] Knop GC, Seeliger MW, Thiel F, Mataruga A, Kaupp UB, Friedburg C, Tanimoto N,Muller F. Light responses in the mouse retina are prolonged upon targeted deletion ofthe HCN1channel gene. Eur J Neurosci28:2221–2230,2008.
[20] Ishii TM, Takano M, Xie LH, Noma A, Ohmori H. Molecular characterization of thehyperpolarization-activated cation channel in rabbit heart sinoatrial node. J Biol Chem274:12835–12839,1999.
[21] Ludwig A, Zong X, Jeglitsch M, Hofmann F, Biel M. A family ofhyperpolarization-activated mammalian cation channels. Nature393:587–591,1998.
[22] Altomare C, Bucchi A, Camatini E, Baruscotti M, Viscomi C, Moroni A, DiFrancescoD. Integrated allosteric model of voltage gating of HCN channels. J Gen Physiol117:519–532,2001.
[23] Craven KB, Zagotta WN. CNG and HCN channels: two peas, one pod. Annu RevPhysiol68:375–401,2006.
[24] Macri V, Accili EA. Structural elements of instantaneous and slow gating inhyperpolarization-activated cyclic nucleotide-gated channels. J Biol Chem279:16832–16846,2004.
[25] Debanne D, Gastrein P, Campanac E. Queer channels in hippocampal basket cells:h-current without sag. J Physiol574:2,2006.
[26] Proenza C, Angoli D, Agranovich E, Macri V, Accili EA. Pacemaker channels producean instantaneous current. J Biol Chem277:5101–5109,2002.
[27] Erickson KR, Ronnekleiv OK, Kelly MJ. Electrophysiology of guinea-pig supraopticneurones: role of a hyperpolarization-activated cation current in phasic firing. J Physiol460:407–425,1993.
[28] Womble MD, Moises HC. Hyperpolarization-activated currents in neurons of the ratbasolateral amygdala. J Neurophysiol70:2056–2065,1993.
[29] Demir SS, Clark JW, Murphey CR, Giles WR. A mathematical model of a rabbitsinoatrial node cell. Am J Physiol Cell Physiol266: C832–C852,1994.
[30] DiFrancesco D. The contribution of the “pacemaker” current (if) to generation ofspontaneous activity in rabbit sino-atrial node myocytes. J Physiol434:23–40,1991.
[31] Edman A, Gestrelius S, Grampp W. Current activation by membrane hyperpolarizationin the slowly adapting lobster stretch receptor neurone. J Physiol384:671–690,1987.
[32] Mercuri NB, Bonci A, Calabresi P, Stefani A, Bernardi G. Properties of thehyperpolarization-activated cation current Ih in rat midbrain dopaminergic neurons. EurJ Neurosci7:462–469,1995.
[33] Pape HC. Queer current and pacemaker: the hyperpolarizationactivated cation currentin neurons. Annu Rev Physiol58:299–327,1996.
[34] Banks MI, Pearce RA, Smith PH. Hyperpolarization-activated cation current (Ih) inneurons of the medial nucleus of the trapezoid body: voltage-clamp analysis andenhancement by norepinephrine and cAMP suggest a modulatory mechanism in theauditory brain stem. J Neurophysiol70:1420–1432,1993.
[35] Baruscotti M, Bucchi A, Difrancesco D. Physiology and pharmacology of the cardiacpacemaker (“funny”) current. Pharmacol Ther107:59–79,2005.
[36] Accili EA, DiFrancesco D. Inhibition of the hyperpolarizationactivated current (if) ofrabbit SA node myocytes by niflumic acid. Pflu¨ gers Arch431:757–762,1996.
[37] Fares N, Bois P, Lenfant J, Potreau D. Characterization of a hyperpolarization-activatedcurrent in dedifferentiated adult rat ventricular cells in primary culture. J Physiol506:73–82,1998.
[38] DiFrancesco D, Tortora P. Direct activation of cardiac pacemaker channels byintracellular cyclic AMP. Nature351:145–147,1991.
[39] Bobker DH, Williams JT. Serotonin augments the cationic current Ih in central neurons.Neuron2:1535–1540,1989.
[40] Tokimasa T, Akasu T. Cyclic AMP regulates an inward rectifying sodium-potassiumcurrent in dissociated bull-frog sympathetic neurones. J Physiol420:409–429,1990.
[41] Wainger BJ, DeGennaro M, Santoro B, Siegelbaum SA, Tibbs GR. Molecularmechanism of cAMP modulation of HCN pacemaker channels. Nature411:805–810,2001.
[42] Pape HC. Adenosine promotes burst activity in guinea-pig geniculocortical neuronesthrough two different ionic mechanisms. J Physiol447:729–753,1992.
[43] Erickson KR, Ronnekleiv OK, Kelly MJ. Electrophysiology of guinea-pig supraopticneurones: role of a hyperpolarization-activated cation current in phasic firing. J Physiol460:407–425,1993.
[44] Garratt JC, Alreja M, Aghajanian GK. LSD has high efficacy relative to serotonin inenhancing the cationic current Ih: intracellular studies in rat facial motoneurons.Synapse13:123–134,1993.
[45] Kiehn O, Harris-Warrick RM.5-HT modulation of hyperpolarization-activated inwardcurrent and calcium-dependent outward current in a crustacean motor neuron. JNeurophysiol68:496–508,1992.
[46] Ludwig A, Zong X, Stieber J, Hullin R, Hofmann F, Biel M. Two pacemaker channelsfrom human heart with profoundly different activation kinetics. EMBO J18:2323–2329,1999.
[47] Santoro B, Liu DT, Yao H, Bartsch D, Kandel ER, Siegelbaum SA, Tibbs GR.Identification of a gene encoding a hyperpolarization-activated pacemaker channel ofbrain. Cell93:717–729,1998.
[48] Seifert R, Scholten A, Gauss R, Mincheva A, Lichter P, Kaupp UB. Molecularcharacterization of a slowly gating human hyperpolarization-activated channelpredominantly expressed in thalamus, heart, and testis. Proc Natl Acad Sci USA96:9391–9396,1999.
[49] DiFrancesco D, Tortora P. Direct activation of cardiac pacemaker channels byintracellular cyclic AMP. Nature351:145–147,1991.
[50] Luthi A, McCormick DA. Modulation of a pacemaker current through Ca2_-inducedstimulation of cAMP production. Nat Neurosci2:634–641,1999.
[51] Pape HC, Mager R. Nitric oxide controls oscillatory activity in thalamocortical neurons.Neuron9:441–448,1992.
[52] Musialek P, Lei M, Brown HF, Paterson DJ, Casadei B. Nitric oxide can increase heartrate by stimulating the hyperpolarizationactivated inward current, I(f). Circ Res81:60–68,1997.
[53] Gauss R, Seifert R, Kaupp UB. Molecular identification of ahyperpolarization-activated channel in sea urchin sperm. Nature393:583–587,1998.
[54] Ludwig A, Zong X, Jeglitsch M, Hofmann F, Biel M. A family ofhyperpolarization-activated mammalian cation channels. Nature393:587–591,1998.
[55] Zagotta WN, Olivier NB, Black KD, Young EC, Olson R, Gouaux E. Structural basisfor modulation and agonist specificity of HCN pacemaker channels. Nature425:200–205,2003.
[56] Vargas G, Lucero MT. Modulation by PKA of the hyperpolarization-activated current(Ih) in cultured rat olfactory receptor neurons. J Membr Biol188:115–125,2002.
[57] DiFrancesco D. Characterization of single pacemaker channels in cardiac sino-atrialnode cells. Nature324:470–473,1986.
[58] Van Ginneken AC, Giles W. Voltage clamp measurements of thehyperpolarization-activated inward current I(f) in single cells from rabbit sino-atrialnode. J Physiol434:57–83,1991.
[59] Ho WK, Brown HF, Noble D. High selectivity of the i(f) channel to Na_and K_inrabbit isolated sinoatrial node cells. Pflu¨ gers Arch426:68–74,1994.
[60] Wollmuth LP, Hille B. Ionic selectivity of Ih channels of rod photoreceptors in tigersalamanders. J Gen Physiol100:749–765,1992.
[61] Ludwig A, Zong X, Jeglitsch M, Hofmann F, Biel M. A family ofhyperpolarization-activated mammalian cation channels. Nature393:587–591,1998.
[62] Tanaka E, Higashi H, Nishi S. Membrane properties of guinea pig cingulate corticalneurons in vitro. J Neurophysiol65:808–821,1991.
[63] Frace AM, Maruoka F, Noma A. External K_increases Na conductance of thehyperpolarization-activated current in rabbit cardiac pacemaker cells. Pflu¨ gers Arch421:97–99,1992.
[64] DiFrancesco D. A study of the ionic nature of the pace-maker current in calf Purkinjefibres. J Physiol314:377–393,1981.
[65] Frace AM, Maruoka F, Noma A. Control of the hyperpolarization-activated cationcurrent by external anions in rabbit sino-atrial node cells. J Physiol453:307–318,1992.
[66] Yu X, Chen XW, Zhou P, Yao L, Liu T, Zhang B, Li Y, Zheng H, Zheng LH, ZhangCX, Bruce I, Ge JB, Wang SQ, Hu ZA, Yu HG, Zhou Z. Calcium influx through Ifchannels in rat ventricular myocytes. Am J Physiol Cell Physiol292: C1147–C1155,2007.
[67] Yu X, Duan KL, Shang CF, Yu HG, Zhou Z. Calcium influx throughhyperpolarization-activated cation channels [I(h) channels] contributes toactivity-evoked neuronal secretion. Proc Natl Acad Sci USA101:1051–1056,2004.
[68] Kole MH, Hallermann S, Stuart GJ. Single Ih channels in pyramidal neuron dendrites:properties, distribution, and impact on action potential output. J Neurosci26:1677–1687,2006.
[69] Michels G, Er F, Khan I, Sudkamp M, Herzig S, Hoppe UC. Single-channel propertiessupport a potential contribution of hyperpolarization-activated cyclic nucleotide-gatedchannels and If to cardiac arrhythmias. Circulation111:399–404,2005.
[70] Poolos NP, Bullis JB, Roth MK. Modulation of h-channels in hippocampal pyramidalneurons by p38mitogen-activated protein kinase. J Neurosci26:7995–8003,2006.
[71] Michels G, Er F, Khan IF, Endres-Becker J, Brandt MC, Gassanov N, Johns DC, HoppeUC. K channel regulator KCR1suppresses heart rhythm by modulating the pacemakercurrent I(f). PLoS ONE3: e1511,2008.
[72] DiFrancesco D. Block and activation of the pace-maker channel in calf Purkinje fibres:effects of potassium, caesium and rubidium. J Physiol329:485–507,1982.
[73] Deal KK, England SK, Tamkun MM. Molecular physiology of cardiac potassiumchannels. Physiol Rev76:49–67,1996.
[74] Nerbonne JM, Kass RS. Molecular physiology of cardiac repolarization. Physiol Rev85:1205–1253,2005.
[75] Biel M, Michalakis S. Function and dysfunction of CNG channels: insights fromchannelopathies and mouse models. Mol Neurobiol35:266–277,2007.
[76] Yu FH, Yarov-Yarovoy V, Gutman GA, Catterall WA. Overview of molecularrelationships in the voltage-gated ion channel superfamily. Pharmacol Rev57:387–395,2005.
[77] Gauss R, Seifert R, Kaupp UB. Molecular identification of ahyperpolarization-activated channel in sea urchin sperm. Nature393:583–587,1998.
[78] Ishii TM, Takano M, Xie LH, Noma A, Ohmori H. Molecular characterization of thehyperpolarization-activated cation channel in rabbit heart sinoatrial node. J Biol Chem274:12835–12839,1999.
[79] Krieger J, Strobel J, Vogl A, Hanke W, Breer H. Identification of a cyclic nucleotide-and voltage-activated ion channel from insect antennae. Insect Biochem Mol Biol29:255–267,1999.
[80] Shi W, Wymore R, Yu H, Wu J, Wymore RT, Pan Z, Robinson RB, Dixon JE,McKinnon D, Cohen IS. Distribution and prevalence of hyperpolarization-activatedcation channel (HCN) mRNA expression in cardiac tissues. Circ Res85: e1–6,1999
[81] Jackson HA, Marshall CR, Accili EA. Evolution and structural diversification ofhyperpolarization-activated cyclic nucleotidegated channel genes. Physiol Gen29:231–245,2007.
[82] Gisselmann G, Marx T, Bobkov Y, Wetzel CH, Neuhaus EM, Ache BW, Hatt H.Molecular and functional characterization of an I(h)-channel from lobster olfactoryreceptor neurons. Eur J Neurosci21:1635–1647,2005.
[83] Marx T, Gisselmann G, Stortkuhl KF, Hovemann BT, Hatt H. Molecular cloning of aputative voltage-and cyclic nucleotide-gated ion channel present in the antennae andeyes of Drosophila melanogaster. Invert Neurosci4:55–63,1999.
[84] Galindo BE, Neill AT, Vacquier VD. A new hyperpolarizationactivated, cyclicnucleotide-gated channel from sea urchin sperm flagella. Biochem Biophys ResCommun334:96–101,2005.
[85] Altomare C, Terragni B, Brioschi C, Milanesi R, Pagliuca C,Viscomi C, Moroni A,Baruscotti M, DiFrancesco D. Heteromeric HCN1-HCN4channels: a comparison withnative pacemaker channels from the rabbit sinoatrial node. J Physiol549:347–359,2003.
[86] Chen S, Wang J, Siegelbaum SA. Properties of hyperpolarization-activated pacemakercurrent defined by coassembly of HCN1and HCN2subunits and basal modulation bycyclic nucleotide. J Gen Physiol117:491–504,2001.
[87] Er F, Larbig R, Ludwig A, Biel M, Hofmann F, Beuckelmann DJ, Hoppe UC.Dominant-negative suppression of HCN channels markedly reduces the nativepacemaker current I(f) and undermines spontaneous beating of neonatalcardiomyocytes. Circulation107:485–489,2003.
[88] Gisselmann G, Gamerschlag B, Sonnenfeld R, Marx T, Neuhaus EM, Wetzel CH, HattH. Variants of the Drosophila melanogaster Ih-channel are generated by differentsplicing. Insect Biochem Mol Biol35:505–514,2005.
[89] Gisselmann G, Wetzel CH, Warnstedt M, Hatt H. Functional characterization ofIh-channel splice variants from Apis mellifera. FEBS Lett575:99–104,2004.
[90] Ouyang Q, Goeritz M, Harris-Warrick RM. Panulirus interruptus Ih-channel gene PIIH:modification of channel properties by alternative splicing and role in rhythmic activity.J Neurophysiol97:3880–3892,2007.
[91] Kaupp UB, Seifert R. Molecular diversity of pacemaker ion channels. Annu RevPhysiol63:235–257,2001.
[92] DiFrancesco D, Ferroni A, Mazzanti M, Tromba C. Properties of thehyperpolarizing-activated current (if) in cells isolated from the rabbit sino-atrial node. JPhysiol377:61–88,1986.
[93] Ishii TM, Takano M, Ohmori H. Determinants of activation kinetics in mammalianhyperpolarization-activated cation channels. J Physiol537:93–100,2001.
[94] Stieber J, Stockl G, Herrmann S, Hassfurth B, Hofmann F. Functional expression of thehuman HCN3channel. J Biol Chem280:34635–34643,2005.
[95] Wainger BJ, DeGennaro M, Santoro B, Siegelbaum SA, Tibbs GR. Molecularmechanism of cAMP modulation of HCN pacemaker channels. Nature411:805–810,2001.
[96] Stieber J, Stockl G, Herrmann S, Hassfurth B, Hofmann F. Functional expression of thehuman HCN3channel. J Biol Chem280:34635–34643,2005.
[97] Chaplan SR, Guo HQ, Lee DH, Luo L, Liu C, Kuei C, VelumianAA, Butler MP,Brown SM, Dubin AE. Neuronal hyperpolarization-activated pacemaker channels driveneuropathic pain. J Neurosci23:1169–1178,2003.
[98] Mistrik P, Mader R, Michalakis S, Weidinger M, Pfeifer A, Biel M. The murine HCN3gene encodes a hyperpolarization-activated cation channel with slow kinetics andunique response to cyclic nucleotides. J Biol Chem280:27056–27061,2005.
[99] Hardel N, Harmel N, Zolles G, Fakler B, Klocker N. Recycling endosomes supplycardiac pacemaker channels for regulated surface expression. Cardiovasc Res79:52–60,2008.
[100] Hoshi T. Regulation of voltage dependence of the KAT1channel by intracellularfactors. J Gen Physiol105:309–328,1995.
[101] El-Kholy W, MacDonald PE, Fox JM, Bhattacharjee A, Xue T, Gao X, Zhang Y,Stieber J, Li RA, Tsushima RG, Wheeler MB. Hyperpolarization-activated cyclicnucleotide-gated channels in pancreatic beta-cells. Mol Endocrinol21:753–764,2007.
[102] Hisada T, Ordway RW, Kirber MT, Singer JJ, Walsh JV Jr.Hyperpolarization-activated cationic channels in smooth muscle cells are stretchsensitive. Pflu¨ gers Arch417:493–499,1991.
[103] McCloskey KD, Toland HM, Hollywood MA, Thornbury KD, McHale NG.Hyperpolarisation-activated inward current in isolated sheep mesenteric lymphaticsmooth muscle. J Physiol521:201–211,1999.
[104] Okabe K, Inoue Y, Kawarabayashi T, Kajiya H, Okamoto F, Soeda H. Physiologicalsignificance of hyperpolarization-activated inward currents (Ih) in smooth muscle cellsfrom the circular layers of pregnant rat myometrium. Pflu¨ gers Arch439:76–85,1999.
[105] Greenwood IA, Prestwich SA. Characteristics of hyperpolarization-activated cationcurrents in portal vein smooth muscle cells. Am J Physiol Cell Physiol282:C744–C753,2002.
[106] Xiao J, Nguyen TV, Ngui K, Strijbos PJ, Selmer IS, Neylon CB, Furness JB. Molecularand functional analysis of hyperpolarisation-activated nucleotide-gated (HCN) channelsin the enteric nervous system. Neuroscience129:603–614,2004.
[107] Greenwood IA, Prestwich SA. Characteristics of hyperpolarization-activated cationcurrents in portal vein smooth muscle cells. Am J Physiol Cell Physiol282:C744–C753,2002.
[108] Milligan CJ, Edwards IJ, Deuchars J. HCN1ion channel immunoreactivity in spinalcord and medulla oblongata. Brain Res1081:79–91,2006.
[109] Santoro B, Chen S, Luthi A, Pavlidis P, Shumyatsky GP, Tibbs GR, Siegelbaum SA.Molecular and functional heterogeneity of hyperpolarization-activated pacemakerchannels in the mouse CNS. J Neurosci20:5264–5275,2000
[110] Cangiano L, Gargini C, Della Santina L, Demontis GC, Cervetto L. High-pass filteringof input signals by the I(h) current in a non-spiking neuron, the retinal rod bipolar cell.PLoS ONE2: e1327,2007.
[111] Chevaleyre V, Castillo PE. Assessing the role of Ih channels in synaptic transmissionand mossy fiber LTP. Proc Natl Acad Sci USA99:9538–9543,2002.
[112] Moosmang S, Stieber J, Zong X, Biel M, Hofmann F, Ludwig A. Cellular expressionand functional characterization of four hyperpolarization-activated pacemaker channelsin cardiac and neuronal tissues. Eur J Biochem268:1646–1652,2001
[113] Marionneau C, Couette B, Liu J, Li H, Mangoni ME, Nargeot J, Lei M, Escande D,Demolombe S. Specific pattern of ionic channel gene expression associated withpacemaker activity in the mouse heart. J Physiol562:223–234,2005.
[114] Dobrzynski H, Nikolski VP, Sambelashvili AT, Greener ID, Yamamoto M, Boyett MR,Efimov IR. Site of origin and molecular substrate of atrioventricular junctional rhythmin the rabbit heart. Circ Res93:1102–1110,2003.
[115] Shi W, Yu H, Wu J, Zuckerman J, Wymore R. The distribution and prevalence of HCNisoforms in the canine heart and their relation to voltage dependence of If. Biophys J78:e353A,2000.
[116] Fernandez-Velasco M, Goren N, Benito G, Blanco-Rivero J, Bosca L, Delgado C.Regional distribution of hyperpolarizationactivated current (If) andhyperpolarization-activated cyclic nucleotide-gated channel mRNA expression inventricular cells from control and hypertrophied rat hearts. J Physiol553:395–405,2003.
[117] Seccareccia F, Pannozzo F, Dima F, Minoprio A, Menditto A, Lo Noce C, Giampaoli S.Heart rate as a predictor of mortality: the MATISS project. Am J Public Health91:1258–1263,2001.
[118] Doesch AO, Celik S, Ehlermann P, Frankenstein L, Zehelein J, Koch A, Katus HA,Dengler TJ. Heart rate reduction after heart transplantation with beta-blocker versus theselective If channel antagonist ivabradine. Transplantation84:988–996,2007.
[119] Sulfi S, Timmis AD. Ivabradine: the first selective sinus node I(f) channel inhibitor inthe treatment of stable angina. Int J Clin Pract60:222–228,2006.
[120] Bucchi A, Baruscotti M, DiFrancesco D. Current-dependent block of rabbit sino-atrialnode I(f) channels by ivabradine. J Gen Physiol120:1–13,2002.
[121] Thollon C, Bedut S, Villeneuve N, Coge F, Piffard L, Guillaumin JP, Brunel-JacqueminC, Chomarat P, Boutin JA, Peglion JL, Vilaine JP. Use-dependent inhibition of hHCN4by ivabradine and relationship with reduction in pacemaker activity. Br J Pharmacol150:37–46,2007.
[122] Stieber J, Wieland K, Stockl G, Ludwig A, Hofmann F. Bradycardic and proarrhythmicproperties of sinus node inhibitors. Mol Pharmacol69:1328–1337,2006.
[123] DiFrancesco D. Some properties of the UL-FS49block of thehyperpolarization-activated current [i(f)] in sino-atrial node myocytes. Pflu¨ gers Arch427:64–70,1994.
[124] BoSmith RE, Briggs I, Sturgess NC. Inhibitory actions of ZENECA ZD7288onwhole-cell hyperpolarization activated inward current (If) in guinea-pig dissociatedsinoatrial node cells. Br J Pharmacol110:343–349,1993.
[125] Snyders DJ, Van Bogaert PP. Alinidine modifies the pacemaker current in sheepPurkinje fibers. Pflu¨ gers Arch410:83–91,1987.
[126] Knaus A, Zong X, Beetz N, Jahns R, Lohse MJ, Biel M, Hein L. Direct inhibition ofcardiac hyperpolarization-activated cyclic nucleotide-gated pacemaker channels byclonidine. Circulation115:872–880,2007.
[127] Cervetto L, Demontis GC, Gargini C. Cellular mechanisms underlying thepharmacological induction of phosphenes. Br J Pharmacol150:383–390,2007.
[128] Sanchez-Alonso JL, Halliwell JV, Colino A. ZD7288inhibits T-type calcium currentin rat hippocampal pyramidal cells. Neurosci Lett439:275–280,2008.
[1] Cajal SR. Sur les ganglions et plexus nerveux de l'intestin. C R Seances Soc Biol Fil45:217–223,1893.
[2] Cajal SR. Histologie du Système Nerveux de l'Homme et des Vertébrés. Paris: Maloine,1911.
[3] Thuneberg L. One hundred years of interstitial cells of Cajal. Microsc Res Tech47:223–238,1999.
[4] Sanders KM. A case for interstitial cells of Cajal as pacemakers and mediators ofneurotransmission in the gastrointestinal tract. Gastroenterology111:492–515,1996.
[5] Rumessen JJ and Thuneberg L. Pacemaker cells in the gastrointestinal tract: interstitialcells of Cajal. Scand J Gastroenterol216(Suppl):82–94,1996.
[6] Cousins HM et al. Electrical coupling between the myenteric interstitial cells of Cajal andadjacent muscle layers in the guinea-pig gastric antrum. J Physiol550:829–84,2003.
[7] Ward SM and Sanders KM. Interstitial cells of Cajal: primary targets of enteric motorinnervation. Anat Rec262:125–135,2001.
[8] Horowitz B et al. Cellular and molecular basis for electrical rhythmicity ingastrointestinal muscles. Annu Rev Physiol61:19–43,1999.
[9] Komuro T et al. Ultrastructural characterization of the interstitial cells of Cajal. ArchHistol Cytol62:295–316,1999.
[10] Ward SM et al. Propagation of slow waves requires IP3receptors and mitochondrial Ca2+uptake in canine colonic muscles. J Physiol549:207–218,2003.
[11] Koh SD et al. Conductances responsible for slow wave generation and propagation ininterstitial cells of Cajal. Curr Opin Pharmacol3:579–582,2003.
[12] Mikkelsen HB et al. Action potential generation, Kit receptor immunohistochemistry andmorphology of steel-Dickie (Sl/Sld) mutant mouse small intestine. NeurogastroenterolMotil10:11–26,1998.
[13] Sanders KM et al. Physiology and pathophysiology of the interstitial cells of Cajal: frombench to bedside. IV. Genetic and animal models of GI motility disorders caused by lossof interstitial cells of Cajal. Am J Physiol Gastrointest Liver Physiol282:747–756,2002.
[14] Smet PJ et al. Distribution of nitric oxide synthase-immunoreactive nerves andidentification of the cellular targets of nitric oxide in guinea-pig and human urinarybladder by cGMP immunohistochemistry. Neuroscience71:337–348,1996.
[15] Sergeant GP et al. Specialised pacemaking cells in the rabbit urethra. J Physiol526:359–366,2000.
[16] Sergeant GP et al. Spontaneous Ca2+activated Cl-currents in isolated urethral smoothmuscle cells. J Urol166:1161–1166,2001.
[17] Hollywood MA et al. Activation of Ca2+-activated Cl-current by depolarizing steps inrabbit urethral interstitial cells. Am J Physiol Cell Physiol285:327–333,2003.
[18] Johnston L et al. Calcium oscillations in interstitial cells of the rabbit urethra. J Physiol565:449–461,2005.
[19] McCloskey KD and Gurney AM. Kit positive cells in the guinea pig bladder. J Urol168:832–836(2002)
[20] Davidson RA and McCloskey KD. Morphology and localization of interstitial cells in theguinea-pig bladder: structural relationships with smooth muscle and neurons. J Urol173:1385–1390,2005.
[21] Hashitani H et al. Role of interstitial cells and gap junctions in the transmission ofspontaneous Ca2+signals in detrusor smooth muscles of the guinea-pig urinary bladder. JPhysiol559:567–581,2004.
[22] Sui GP et al. Gap junctions and connexin expression in human suburothelial interstitialcells. BJU Int90:118–129,2002.
[23] Gosling JA and Dixon JS. Structural evidence in support of an urinary tract pacemaker. BrJ Urol44:550–560,1972.
[24] Klemm MF et al. Identification of the cells underlying pacemaker activity in theguinea-pig upper urinary tract. J Physiol519:867–884,1999.
[25] Pezzone MA et al. Identification of c-kit-positive cells in the mouse ureter: the interstitialcells of Cajal of the urinary tract. Am J Physiol Renal Physiol284:925–929,2003.
[26] Metzger R et al. Cajal-like cells in the human upper urinary tract. J Urol172:769–772,2004.
[27] Solari V et al. Altered expression of interstitial cells of Cajal in congenital ureteropelvicjunction obstruction. J Urol170:2420–2422,2003.
[28] Exintaris B et al. Spontaneous slow wave and contractile activity of the guinea pigprostate. J Urol168:315–322,2002.
[29] Van der Aa F et al. Interstitial cells in the human prostate: a new therapeutic target?Prostate56:250–255,2003.
[30] Hashitani H and Suzuki H. Identification of interstitial cells of Cajal in corporal tissues ofthe guinea-pig penis. Br J Pharmacol141:199–204,2004.
[31] Burton LD et al. P2X2receptor expression by interstitial cells of Cajal in vas deferensimplicated in semen emission. Auton Neurosci84:147–161,2000.
[32] Drake MJ et al. Morphology, phenotype and ultrastructure of fibroblastic cells fromnormal and neuropathic human detrusor: absence of myofibroblast characteristics. J Urol169:1573–1576,2003.
[33] Wu C et al. Purinergic regulation of guinea pig suburothelial myofibroblasts. J Physiol559:231–243,2004.
[34] Wiseman OJ et al. The role of the human bladder lamina propria myofibroblast. BJU Int91:89–93,2003.
[35] Powell DW et al. Myofibroblasts. I. Paracrine cells important in health and disease. Am JPhysiol277:1–9,1999.
[36] Hashitani H et al. Properties of spontaneous depolarizations in circular smooth musclecells of rabbit urethra. Br J Pharmacol118:1627–1632,1996.
[37] Cotton KD et al. Ca2+current and Ca2+-activated chloride current in isolated smoothmuscle cells of the sheep urethra. J Physiol505:121–131,1997.
[38] Turner WH and Brading AF. Smooth muscle of the bladder in the normal and the diseasedstate: pathophysiology, diagnosis and treatment. Pharmacol Ther75:77–110,1997.
[39] Daniel EE et al. Structural bases for neural and myogenic control of human detrusormuscle. Can J Physiol Pharmacol61:1247–1273,1983.
[40] Bramich NJ and Brading AF. Electrical properties of smooth muscle in the guinea-pigurinary bladder. J Physiol492:185–198,1996.
[41] Hanani M and Brading AF. Electrical coupling in smooth muscles. Is it universal? J BasicClin Physiol Pharmacol11:321–330,2000.
[42] Hashitani H and Brading AF. Electrical properties of detrusor smooth muscles from thepig and human urinary bladder. Br J Pharmacol140:146–158,2003.
[43] Hashitani H and Brading AF. Ionic basis for the regulation of spontaneous excitation indetrusor smooth muscle cells of the guinea-pig urinary bladder. Br J Pharmacol140:159–169,2003.
[44] Hashitani H et al. Origin and propagation of spontaneous excitation in smooth muscle ofthe guinea-pig urinary bladder. J Physiol530:273–286,2001.
[45] Kubota Y et al. Investigation of the effect of the c-kit inhibitor Glivec on isolatedguinea-pig detrusor preparations. Auton Neurosci115:64–73,2004.
[46] Biers SM. Novel pharmological treatments for detrusor overactivity [thesis]. Oxford:Oxford University,2005.
[47] Gillespie JI. The autonomous bladder: a view of the origin of bladder overactivity andsensory urge. BJU Int93:478–483,2004.
[48] De Ridder D et al. Nitric oxide synthase expression in neurogenic bladder disease: a pilotstudy. Acta Neurol Belg99:57–60,1999.
[49] Moon A. Influence of nitric oxide signalling pathways on pre-contracted human detrusorsmooth muscle in vitro. BJU Int89:942–949,2002.
[50] Ost D et al. Topography of the vanilloid receptor in the human bladder: more than just thenerve fibers. J Urol168:293–297,2002.
[51] Fry CH et al. Cell biology. In Incontinence:3rd International Consultation onIncontinence,313–362(Eds Abrams P et al.). Plymouth: Health Publication Ltd,2005.
[52] Kubota Y et al.: The effects of imatinib mesylate (Glivec) as a c-kit tyrosine kinaseinhibitor in the guinea-pig urinary bladder. Neurourol Urodyn,25:205-210,2006.
[53] Piotrowska AP et al. Interstitial cells of Cajal in the human normal urinary bladder and inthe bladder of patients with megacystis-microcolon intestinal hypoperistalsis syndrome.BJU Int94:143–146,2004.
2. Brading AF: A myogenic basis for the overactive bladder. Urology1997,50(6ASuppl):57-67; discussion68-73.
3. Hashitani H, Fukuta H, Takano H, Klemm MF, Suzuki H: Origin and propagation ofspontaneous excitation in smooth muscle of the guinea-pig urinary bladder. J Physiol2001,530(Pt2):273-286.
4. Lang RJ, Hashitani H, Tonta MA, Parkington HC, Suzuki H: Spontaneous electricaland Ca2+signals in typical and atypical smooth muscle cells and interstitial cell ofCajal-like cells of mouse renal pelvis. J Physiol2007,583(Pt3):1049-1068.
5. Guay DR: Tolterodine, a new antimuscarinic drug for treatment of bladder overactivity.Pharmacotherapy1999,19(3):267-280.
6. Meng E, Young JS, Brading AF: Spontaneous activity of mouse detrusor smoothmuscle and the effects of the urothelium. Neurourol Urodyn2008,27(1):79-87.
7. Thuneberg L: One hundred years of interstitial cells of Cajal. Microsc Res Tech1999,47(4):223-238.
8. Hanani M, Freund HR: Interstitial cells of Cajal--their role in pacing and signaltransmission in the digestive system. Acta Physiol Scand2000,170(3):177-190.
9. McCloskey KD, Gurney AM: Kit positive cells in the guinea pig bladder. J Urol2002,168(2):832-836.
10. Popescu LM, Ciontea SM, Cretoiu D, Hinescu ME, Radu E, Ionescu N, Ceausu M,Gherghiceanu M, Braga RI, Vasilescu F et al: Novel type of interstitial cell (Cajal-like)in human fallopian tube. J Cell Mol Med2005,9(2):479-523.
11. Ciontea SM, Radu E, Regalia T, Ceafalan L, Cretoiu D, Gherghiceanu M, Braga RI,Malincenco M, Zagrean L, Hinescu ME et al: C-kit immunopositive interstitial cells(Cajal-type) in human myometrium. J Cell Mol Med2005,9(2):407-420.
12. Popescu LM, Hinescu ME, Ionescu N, Ciontea SM, Cretoiu D, Ardelean C: Interstitialcells of Cajal in pancreas. J Cell Mol Med2005,9(1):169-190.
13. Popescu LM, Andrei F, Hinescu ME: Snapshots of mammary gland interstitial cells:methylene-blue vital staining and c-kit immunopositivity. J Cell Mol Med2005,9(2):476-477.
14.沈文浩,李为兵,熊恩庆,宋波,卢根生,金锡御:胃肠道起搏细胞ICCs在豚鼠泌尿道分布研究.第三军医大学学报2006,28(2):172-173.
15. Wang Y, Fang Q, Lu Y, Song B, Li W, Li L: Effects of mechanical stretch oninterstitial cells of Cajal in guinea pig bladder. J Surg Res2010,164(1):e213-219.
16. Solari V, Piotrowska AP, Puri P: Altered expression of interstitial cells of Cajal incongenital ureteropelvic junction obstruction. J Urol2003,170(6Pt1):2420-2422.
17. Schwentner C, Oswald J, Lunacek A, Fritsch H, Deibl M, Bartsch G, Radmayr C: Lossof interstitial cells of Cajal and gap junction protein connexin43at the vesicoureteraljunction in children with vesicoureteral reflux. J Urol2005,174(5):1981-1986.
18. Kubota Y, Hashitani H, Shirasawa N, Kojima Y, Sasaki S, Mabuchi Y, Soji T, SuzukiH, Kohri K: Altered distribution of interstitial cells in the guinea pig bladder followingbladder outlet obstruction. Neurourol Urodyn2008,27(4):330-340.
19. McCloskey KD, Anderson UA, Davidson RA, Bayguinov YR, Sanders KM, Ward SM:Comparison of mechanical and electrical activity and interstitial cells of Cajal inurinary bladders from wild-type and W/Wv mice. Br J Pharmacol2009,156(2):273-283.
20. Davidson RA, McCloskey KD: Morphology and localization of interstitial cells in theguinea pig bladder: structural relationships with smooth muscle and neurons. J Urol2005,173(4):1385-1390.
21. El-Kholy W, MacDonald PE, Fox JM, Bhattacharjee A, Xue T, Gao X, Zhang Y,Stieber J, Li RA, Tsushima RG et al: Hyperpolarization-activated cyclicnucleotide-gated channels in pancreatic beta-cells. Mol Endocrinol2007,21(3):753-764.
22. Seifert R, Scholten A, Gauss R, Mincheva A, Lichter P, Kaupp UB: Molecularcharacterization of a slowly gating human hyperpolarization-activated channelpredominantly expressed in thalamus, heart, and testis. Proc Natl Acad Sci U S A1999,96(16):9391-9396.
23. Benham CD, Bolton TB, Denbigh JS, Lang RJ: Inward rectification in freshly isolatedsingle smooth muscle cells of the rabbit jejunum. J Physiol1987,383:461-476.
24. Green ME, Edwards G, Kirkup AJ, Miller M, Weston AH: Pharmacologicalcharacterization of the inwardly-rectifying current in the smooth muscle cells of the ratbladder. Br J Pharmacol1996,119(8):1509-1518.
25. Xiao J, Nguyen TV, Ngui K, Strijbos PJ, Selmer IS, Neylon CB, Furness JB:Molecular and functional analysis of hyperpolarisation-activated nucleotide-gated(HCN) channels in the enteric nervous system. Neuroscience2004,129(3):603-614.
26. Biel M, Wahl-Schott C, Michalakis S, Zong X: Hyperpolarization-activated cationchannels: from genes to function. Physiol Rev2009,89(3):847-885.
27. Hashitani H, Yanai Y, Suzuki H: Role of interstitial cells and gap junctions in thetransmission of spontaneous Ca2+signals in detrusor smooth muscles of theguinea-pig urinary bladder. J Physiol2004,559(Pt2):567-581.
28. Sui GP, Rothery S, Dupont E, Fry CH, Severs NJ: Gap junctions and connexinexpression in human suburothelial interstitial cells. BJU Int2002,90(1):118-129.
29. Anderson UA, Carson C, McCloskey KD: KCNQ currents and their contribution toresting membrane potential and the excitability of interstitial cells of Cajal from theguinea pig bladder. J Urol2009,182(1):330-336.
30. Johnston L, Carson C, Lyons AD, Davidson RA, McCloskey KD: Cholinergic-inducedCa2+signaling in interstitial cells of Cajal from the guinea pig bladder. Am J PhysiolRenal Physiol2008,294(3):F645-655.
31. Shafik A, El-Sibai O, Shafik AA, Shafik I: Identification of interstitial cells of Cajal inhuman urinary bladder: concept of vesical pacemaker. Urology2004,64(4):809-813.
32.方强,杨景,潘进洪,封建立,李为兵,王永权,丁励蠡,宋波: P2X嘌呤受体在大鼠膀胱ICCs细胞中的表达.第三军医大学学报2008,30(7):564-566.
33.贾卓敏,张永革,方强,等:胆碱能激动剂卡巴可对大鼠膀胱ICC样细胞内钙流的影响.临床泌尿外科杂志2009,24(5):393-395.
34. Faussone-Pellegrini MS, Thuneberg L: Guide to the identification of interstitial cellsof Cajal. Microsc Res Tech1999,47(4):248-266.
35. Thuneberg L, Peters S: Toward a concept of stretch-coupling in smooth muscle. I.Anatomy of intestinal segmentation and sleeve contractions. Anat Rec2001,262(1):110-124.
36. Johnston L, Woolsey S, Cunningham RM, O'Kane H, Duggan B, Keane P, McCloskeyKD: Morphological expression of KIT positive interstitial cells of Cajal in humanbladder. J Urol2010,184(1):370-377.
37. Pezzone MA, Watkins SC, Alber SM, King WE, de Groat WC, Chancellor MB, FraserMO: Identification of c-kit-positive cells in the mouse ureter: the interstitial cells ofCajal of the urinary tract. Am J Physiol Renal Physiol2003,284(5):F925-929.
38. Noma A, Irisawa H: Membrane currents in the rabbit sinoatrial node cell as studied bythe double microelectrode method. Pflugers Arch1976,364(1):45-52.
39. Nolan MF, Malleret G, Lee KH, Gibbs E, Dudman JT, Santoro B, Yin D, ThompsonRF, Siegelbaum SA, Kandel ER et al: The hyperpolarization-activated HCN1channelis important for motor learning and neuronal integration by cerebellar Purkinje cells.Cell2003,115(5):551-564.
40. Ludwig A, Budde T, Stieber J, Moosmang S, Wahl C, Holthoff K, Langebartels A,Wotjak C, Munsch T, Zong X et al: Absence epilepsy and sinus dysrhythmia in micelacking the pacemaker channel HCN2. EMBO J2003,22(2):216-224.
41. Moosmang S, Biel M, Hofmann F, Ludwig A: Differential distribution of fourhyperpolarization-activated cation channels in mouse brain. Biol Chem1999,380(7-8):975-980.
42. Notomi T, Shigemoto R: Immunohistochemical localization of Ih channel subunits,HCN1-4, in the rat brain. J Comp Neurol2004,471(3):241-276.
43. Stieber J, Hofmann F, Ludwig A: Pacemaker channels and sinus node arrhythmia.Trends Cardiovasc Med2004,14(1):23-28.
44.熊承杰,梅峰,韩娟,田衍平,江忠勇,周德山: HCN2阳性细胞在小鼠胃肠道肌间神经丛内的分布.第三军医大学学报2010,32(5):409-413.
45. Barajas-Lopez C, Berezin I, Daniel EE, Huizinga JD: Pacemaker activity recorded ininterstitial cells of Cajal of the gastrointestinal tract. Am J Physiol1989,257(4Pt1):C830-835.
46. Lin ZH, Han EM, Lee ES, Kim CW, Kim HK, Kim I, Kim YS: A distinct expressionpattern and point mutation of c-kit in papillary renal cell carcinomas. Mod Pathol2004,17(6):611-616.
47. Oberritter Z, Rolle U, Juhasz Z, Cserni T, Puri P: Altered expression of c-kit-positivecells in the ureterovesical junction after surgically created vesicoureteral reflux.Pediatr Surg Int2009,25(12):1103-1107.
48. Klemm MF, Exintaris B, Lang RJ: Identification of the cells underlying pacemakeractivity in the guinea-pig upper urinary tract. J Physiol1999,519Pt3:867-884.
49. Lyons AD, Gardiner TA, McCloskey KD: Kit-positive interstitial cells in the rabbiturethra: structural relationships with nerves and smooth muscle. BJU Int2007,99(3):687-694.
50. Shafik A, Shafik I, el-Sibai O: Identification of c-kit-positive cells in the humanprostate: the interstitial cells of Cajal. Arch Androl2005,51(5):345-351.
51. Ordog T, Redelman D, Horowitz NN, Sanders KM: Immunomagnetic enrichment ofinterstitial cells of Cajal. Am J Physiol Gastrointest Liver Physiol2004,286(2):G351-360.
52. Liu HN, Ohya S, Furuzono S, Wang J, Imaizumi Y, Nakayama S: Co-contribution ofIP3R and Ca2+influx pathways to pacemaker Ca2+activity in stomach ICC. J BiolRhythms2005,20(1):15-26.
53. Koh SD, Sanders KM, Ward SM: Spontaneous electrical rhythmicity in culturedinterstitial cells of cajal from the murine small intestine. J Physiol1998,513(Pt1):203-213.
54. Nakamura K, Shibata Y: Connexin43expression in network-forming cells at thesubmucosal-muscular border of guinea pig and dog colon. Cells Tissues Organs1999,165(1):16-21.
55. Huizinga JD, Zhu Y, Ye J, Molleman A: High-conductance chloride channels generatepacemaker currents in interstitial cells of Cajal. Gastroenterology2002,123(5):1627-1636.
56. Walker RL, Koh SD, Sergeant GP, Sanders KM, Horowitz B: TRPC4currents haveproperties similar to the pacemaker current in interstitial cells of Cajal. Am J PhysiolCell Physiol2002,283(6):C1637-1645.
57. Lavoie B, Balemba OB, Nelson MT, Ward SM, Mawe GM: Morphological andphysiological evidence for interstitial cell of Cajal-like cells in the guinea piggallbladder. J Physiol2007,579(Pt2):487-501.
58. Torihashi S, Fujimoto T, Trost C, Nakayama S: Calcium oscillation linked topacemaking of interstitial cells of Cajal: requirement of calcium influx and localizationof TRP4in caveolae. J Biol Chem2002,277(21):19191-19197.
59. Johnston L, Sergeant GP, Hollywood MA, Thornbury KD, McHale NG: Calciumoscillations in interstitial cells of the rabbit urethra. J Physiol2005,565(Pt2):449-461.
60. Laskay G, Varhelyi T, Dale RE, Dexter TM: Role of interleukin-3in the regulation ofintracellular K+homeostasis in cultured murine haemopoietic cells. Biochem BiophysRes Commun1995,214(2):348-353.
61. Grieshaber S, Swanson JA, Hackstadt T: Determination of the physical environmentwithin the Chlamydia trachomatis inclusion using ion-selective ratiometric probes.Cell Microbiol2002,4(5):273-283.
62. Andersson B, Janson V, Behnam-Motlagh P, Henriksson R, Grankvist K: Induction ofapoptosis by intracellular potassium ion depletion: using the fluorescent dye PBFI in a96-well plate method in cultured lung cancer cells. Toxicol In Vitro2006,20(6):986-994.
63. Yu X, Duan KL, Shang CF, Yu HG, Zhou Z: Calcium influx throughhyperpolarization-activated cation channels (I(h) channels) contributes toactivity-evoked neuronal secretion. Proc Natl Acad Sci U S A2004,101(4):1051-1056.
64. Yu FH, Catterall WA: The VGL-chanome: a protein superfamily specialized forelectrical signaling and ionic homeostasis. Sci STKE2004,2004(253):re15.
65. Doyle DA, Morais Cabral J, Pfuetzner RA, Kuo A, Gulbis JM, Cohen SL, Chait BT,MacKinnon R: The structure of the potassium channel: molecular basis of K+conduction and selectivity. Science1998,280(5360):69-77.
66. Zhou Y, Morais-Cabral JH, Kaufman A, MacKinnon R: Chemistry of ion coordinationand hydration revealed by a K+channel-Fab complex at2.0A resolution. Nature2001,414(6859):43-48.
67. Shi N, Ye S, Alam A, Chen L, Jiang Y: Atomic structure of a Na+-and K+-conductingchannel. Nature2006,440(7083):570-574.
68. Yang J, Ellinor PT, Sather WA, Zhang JF, Tsien RW: Molecular determinants of Ca2+selectivity and ion permeation in L-type Ca2+channels. Nature1993,366(6451):158-161.
69. Zagotta WN: Membrane biology: permutations of permeability. Nature2006,440(7083):427-429.
70. Azene EM, Xue T, Li RA: Molecular basis of the effect of potassium onheterologously expressed pacemaker (HCN) channels. J Physiol2003,547(Pt2):349-356.
71. Er F, Larbig R, Ludwig A, Biel M, Hofmann F, Beuckelmann DJ, Hoppe UC:Dominant-negative suppression of HCN channels markedly reduces the nativepacemaker current I(f) and undermines spontaneous beating of neonatalcardiomyocytes. Circulation2003,107(3):485-489.
72. Macri V, Proenza C, Agranovich E, Angoli D, Accili EA: Separable gatingmechanisms in a Mammalian pacemaker channel. J Biol Chem2002,277(39):35939-35946.
73. Much B, Wahl-Schott C, Zong X, Schneider A, Baumann L, Moosmang S, Ludwig A,Biel M: Role of subunit heteromerization and N-linked glycosylation in the formationof functional hyperpolarization-activated cyclic nucleotide-gated channels. J BiolChem2003,278(44):43781-43786.
74. Xue T, Marban E, Li RA: Dominant-negative suppression of HCN1-andHCN2-encoded pacemaker currents by an engineered HCN1construct: insights intostructure-function relationships and multimerization. Circ Res2002,90(12):1267-1273.
75. Lang RJ, Takano H, Davidson ME, Suzuki H, Klemm MF: Characterization of thespontaneous electrical and contractile activity of smooth muscle cells in the rat upperurinary tract. J Urol2001,166(1):329-334.
76. Lam M, Shigemasa Y, Exintaris B, Lang RJ, Hashitani H: Spontaneous Ca2+signaling of interstitial cells in the guinea pig prostate. J Urol2011,186(6):2478-2486.
77. Wray S: Smooth muscle intracellular pH: measurement, regulation, and function. Am JPhysiol1988,254(2Pt1):C213-225.
78. DiFrancesco D: Characterization of single pacemaker channels in cardiac sino-atrialnode cells. Nature1986,324(6096):470-473.
79. Kole MH, Hallermann S, Stuart GJ: Single Ih channels in pyramidal neuron dendrites:properties, distribution, and impact on action potential output. J Neurosci2006,26(6):1677-1687.
80. Michels G, Er F, Khan I, Sudkamp M, Herzig S, Hoppe UC: Single-channel propertiessupport a potential contribution of hyperpolarization-activated cyclic nucleotide-gatedchannels and If to cardiac arrhythmias. Circulation2005,111(4):399-404.
81. Simeone TA, Rho JM, Baram TZ: Single channel properties of hyperpolarization-activated cation currents in acutely dissociated rat hippocampal neurones. J Physiol2005,568(Pt2):371-380.
82. Michels G, Er F, Khan IF, Endres-Becker J, Brandt MC, Gassanov N, Johns DC,Hoppe UC: K+channel regulator KCR1suppresses heart rhythm by modulating thepacemaker current If. PLoS One2008,3(1):e1511.
83. Sakmann B, Neher E: Patch clamp techniques for studying ionic channels in excitablemembranes. Annu Rev Physiol1984,46:455-472.
84. Tang G, Wang R: Differential expression of KV and KCa channels in vascular smoothmuscle cells during1-day culture. Pflugers Arch2001,442(1):124-135.
85. Kuga T, Kobayashi S, Hirakawa Y, Kanaide H, Takeshita A: Cell cycle--dependentexpression of L-and T-type Ca2+currents in rat aortic smooth muscle cells in primaryculture. Circ Res1996,79(1):14-19.
86. Ma FH, Higashira H, Ukai Y, Hanai T, Kiwamoto H, Park YC, Kurita T: A newenzymic method for the isolation and culture of human bladder body smooth musclecells. Neurourol Urodyn2002,21(1):71-79.
87. Schot R, van Asselt E, van Mastrigt R: A method for isolating smooth muscle cellsfrom pig urinary bladder with low concentrations of collagenase and papain: therelation between calcium concentration and isolated cell length. Urol Res1993,21(1):49-53.
88. Klockner U, Isenberg G: Action potentials and net membrane currents of isolatedsmooth muscle cells (urinary bladder of the guinea-pig). Pflugers Arch1985,405(4):329-339.
89. Bean BP, Sturek M, Puga A, Hermsmeyer K: Calcium channels in muscle cellsisolated from rat mesenteric arteries: modulation by dihydropyridine drugs. Circ Res1986,59(2):229-235.
90. Chen J, Piper DR, Sanguinetti MC: Voltage sensing and activation gating of HCNpacemaker channels. Trends Cardiovasc Med2002,12(1):42-45.
91. Biel M, Schneider A, Wahl C: Cardiac HCN channels: structure, function, andmodulation. Trends Cardiovasc Med2002,12(5):206-212.
92. Fernandez-Velasco M, Goren N, Benito G, Blanco-Rivero J, Bosca L, Delgado C:Regional distribution of hyperpolarization-activated current (If) andhyperpolarization-activated cyclic nucleotide-gated channel mRNA expression inventricular cells from control and hypertrophied rat hearts. J Physiol2003,553(Pt2):395-405.
93. Chen K, Aradi I, Thon N, Eghbal-Ahmadi M, Baram TZ, Soltesz I: Persistentlymodified h-channels after complex febrile seizures convert the seizure-inducedenhancement of inhibition to hyperexcitability. Nat Med2001,7(3):331-337.
94. Gold MS: Spinal nerve ligation: what to blame for the pain and why. Pain2000,84(2-3):117-120.
[1] Brown HF, Giles W, Noble SJ. Membrane currents underlying activity in frog sinusvenosus. J Physiol271:783–816,1977.
[2] Halliwell JV, Adams PR. Voltage-clamp analysis of muscarinic excitation inhippocampal neurons. Brain Res250:71–92,1982.
[3] Maccaferri G, Mangoni M, Lazzari A, DiFrancesco D. Properties of thehyperpolarization-activated current in rat hippocampal CA1pyramidal cells. JNeurophysiol69:2129–2136,1993.
[4] DiFrancesco D. Pacemaker mechanisms in cardiac tissue. Annu Rev Physiol55:455–472,1993
[5] Brown HF, DiFrancesco D, Noble SJ. How does adrenaline accelerate the heart? Nature280:235–236,1979.
[6] DiFrancesco D, Ducouret P, Robinson RB. Muscarinic modulation of cardiac rate atlow acetylcholine concentrations. Science243:669–671,1989.
[7] DiFrancesco D. A new interpretation of the pace-maker current in calf Purkinje fibres. JPhysiol314:359–376,1981.
[8] Harzheim D, Pfeiffer KH, Fabritz L, Kremmer E, Buch T, Waisman A, Kirchhof P,Kaupp UB, Seifert R. Cardiac pacemaker function of HCN4channels in mice isconfined to embryonic development and requires cyclic AMP. EMBO J27:692–703,2008.
[9] Herrmann S, Stieber J, Stockl G, Hofmann F, Ludwig A. HCN4provides a“depolarization reserve” and is not required for heart rate acceleration in mice. EMBO J26:4423–4432,2007.
[10] Ludwig A, Budde T, Stieber J, Moosmang S, Wahl C, Holthoff K, Langebartels A,Wotjak C, Munsch T, Zong X, Feil S, Feil R, Lancel M, Chien KR, Konnerth A, PapeHC, Biel M, Hofmann F. Absence epilepsy and sinus dysrhythmia in mice lacking thepacemaker channel HCN2. EMBO J22:216–224,2003.
[11] Stieber J, Herrmann S, Feil S, Loster J, Feil R, Biel M, Hofmann F, Ludwig A. Thehyperpolarization-activated channel HCN4is required for the generation of pacemakeraction potentials in the embryonic heart. Proc Natl Acad Sci USA100:15235–15240,2003.
[12] McCormick DA, Huguenard JR. A model of the electrophysiological properties ofthalamocortical relay neurons. J Neurophysiol68:1384–1400,1992.
[13] Day M, Carr DB, Ulrich S, Ilijic E, Tkatch T, Surmeier DJ. Dendritic excitability ofmouse frontal cortex pyramidal neurons is shaped by the interaction among HCN, Kir2,and Kleak channels. J Neurosci25:8776–8787,2005.
[14] Pape HC. Queer current and pacemaker: the hyperpolarizationactivated cation currentin neurons. Annu Rev Physiol58:299–327,1996.
[15] Magee JC. Dendritic hyperpolarization-activated currents modify the integrativeproperties of hippocampal CA1pyramidal neurons. J Neurosci18:7613–7624,1998.
[16] Beaumont V, Zhong N, Froemke RC, Ball RW, Zucker RS. Temporal synaptic taggingby I(h) activation and actin: involvement in long-term facilitation and cAMP-inducedsynaptic enhancement. Neuron33:601–613,2002.
[17] Beaumont V, Zucker RS. Enhancement of synaptic transmission by cyclic AMPmodulation of presynaptic Ih channels. Nat Neurosci3:133–141,2000
[18] Demontis GC, Cervetto L. Vision: how to catch fast signals with slow detectors. NewsPhysiol Sci17:110–114,2002.
[19] Knop GC, Seeliger MW, Thiel F, Mataruga A, Kaupp UB, Friedburg C, Tanimoto N,Muller F. Light responses in the mouse retina are prolonged upon targeted deletion ofthe HCN1channel gene. Eur J Neurosci28:2221–2230,2008.
[20] Ishii TM, Takano M, Xie LH, Noma A, Ohmori H. Molecular characterization of thehyperpolarization-activated cation channel in rabbit heart sinoatrial node. J Biol Chem274:12835–12839,1999.
[21] Ludwig A, Zong X, Jeglitsch M, Hofmann F, Biel M. A family ofhyperpolarization-activated mammalian cation channels. Nature393:587–591,1998.
[22] Altomare C, Bucchi A, Camatini E, Baruscotti M, Viscomi C, Moroni A, DiFrancescoD. Integrated allosteric model of voltage gating of HCN channels. J Gen Physiol117:519–532,2001.
[23] Craven KB, Zagotta WN. CNG and HCN channels: two peas, one pod. Annu RevPhysiol68:375–401,2006.
[24] Macri V, Accili EA. Structural elements of instantaneous and slow gating inhyperpolarization-activated cyclic nucleotide-gated channels. J Biol Chem279:16832–16846,2004.
[25] Debanne D, Gastrein P, Campanac E. Queer channels in hippocampal basket cells:h-current without sag. J Physiol574:2,2006.
[26] Proenza C, Angoli D, Agranovich E, Macri V, Accili EA. Pacemaker channels producean instantaneous current. J Biol Chem277:5101–5109,2002.
[27] Erickson KR, Ronnekleiv OK, Kelly MJ. Electrophysiology of guinea-pig supraopticneurones: role of a hyperpolarization-activated cation current in phasic firing. J Physiol460:407–425,1993.
[28] Womble MD, Moises HC. Hyperpolarization-activated currents in neurons of the ratbasolateral amygdala. J Neurophysiol70:2056–2065,1993.
[29] Demir SS, Clark JW, Murphey CR, Giles WR. A mathematical model of a rabbitsinoatrial node cell. Am J Physiol Cell Physiol266: C832–C852,1994.
[30] DiFrancesco D. The contribution of the “pacemaker” current (if) to generation ofspontaneous activity in rabbit sino-atrial node myocytes. J Physiol434:23–40,1991.
[31] Edman A, Gestrelius S, Grampp W. Current activation by membrane hyperpolarizationin the slowly adapting lobster stretch receptor neurone. J Physiol384:671–690,1987.
[32] Mercuri NB, Bonci A, Calabresi P, Stefani A, Bernardi G. Properties of thehyperpolarization-activated cation current Ih in rat midbrain dopaminergic neurons. EurJ Neurosci7:462–469,1995.
[33] Pape HC. Queer current and pacemaker: the hyperpolarizationactivated cation currentin neurons. Annu Rev Physiol58:299–327,1996.
[34] Banks MI, Pearce RA, Smith PH. Hyperpolarization-activated cation current (Ih) inneurons of the medial nucleus of the trapezoid body: voltage-clamp analysis andenhancement by norepinephrine and cAMP suggest a modulatory mechanism in theauditory brain stem. J Neurophysiol70:1420–1432,1993.
[35] Baruscotti M, Bucchi A, Difrancesco D. Physiology and pharmacology of the cardiacpacemaker (“funny”) current. Pharmacol Ther107:59–79,2005.
[36] Accili EA, DiFrancesco D. Inhibition of the hyperpolarizationactivated current (if) ofrabbit SA node myocytes by niflumic acid. Pflu¨ gers Arch431:757–762,1996.
[37] Fares N, Bois P, Lenfant J, Potreau D. Characterization of a hyperpolarization-activatedcurrent in dedifferentiated adult rat ventricular cells in primary culture. J Physiol506:73–82,1998.
[38] DiFrancesco D, Tortora P. Direct activation of cardiac pacemaker channels byintracellular cyclic AMP. Nature351:145–147,1991.
[39] Bobker DH, Williams JT. Serotonin augments the cationic current Ih in central neurons.Neuron2:1535–1540,1989.
[40] Tokimasa T, Akasu T. Cyclic AMP regulates an inward rectifying sodium-potassiumcurrent in dissociated bull-frog sympathetic neurones. J Physiol420:409–429,1990.
[41] Wainger BJ, DeGennaro M, Santoro B, Siegelbaum SA, Tibbs GR. Molecularmechanism of cAMP modulation of HCN pacemaker channels. Nature411:805–810,2001.
[42] Pape HC. Adenosine promotes burst activity in guinea-pig geniculocortical neuronesthrough two different ionic mechanisms. J Physiol447:729–753,1992.
[43] Erickson KR, Ronnekleiv OK, Kelly MJ. Electrophysiology of guinea-pig supraopticneurones: role of a hyperpolarization-activated cation current in phasic firing. J Physiol460:407–425,1993.
[44] Garratt JC, Alreja M, Aghajanian GK. LSD has high efficacy relative to serotonin inenhancing the cationic current Ih: intracellular studies in rat facial motoneurons.Synapse13:123–134,1993.
[45] Kiehn O, Harris-Warrick RM.5-HT modulation of hyperpolarization-activated inwardcurrent and calcium-dependent outward current in a crustacean motor neuron. JNeurophysiol68:496–508,1992.
[46] Ludwig A, Zong X, Stieber J, Hullin R, Hofmann F, Biel M. Two pacemaker channelsfrom human heart with profoundly different activation kinetics. EMBO J18:2323–2329,1999.
[47] Santoro B, Liu DT, Yao H, Bartsch D, Kandel ER, Siegelbaum SA, Tibbs GR.Identification of a gene encoding a hyperpolarization-activated pacemaker channel ofbrain. Cell93:717–729,1998.
[48] Seifert R, Scholten A, Gauss R, Mincheva A, Lichter P, Kaupp UB. Molecularcharacterization of a slowly gating human hyperpolarization-activated channelpredominantly expressed in thalamus, heart, and testis. Proc Natl Acad Sci USA96:9391–9396,1999.
[49] DiFrancesco D, Tortora P. Direct activation of cardiac pacemaker channels byintracellular cyclic AMP. Nature351:145–147,1991.
[50] Luthi A, McCormick DA. Modulation of a pacemaker current through Ca2_-inducedstimulation of cAMP production. Nat Neurosci2:634–641,1999.
[51] Pape HC, Mager R. Nitric oxide controls oscillatory activity in thalamocortical neurons.Neuron9:441–448,1992.
[52] Musialek P, Lei M, Brown HF, Paterson DJ, Casadei B. Nitric oxide can increase heartrate by stimulating the hyperpolarizationactivated inward current, I(f). Circ Res81:60–68,1997.
[53] Gauss R, Seifert R, Kaupp UB. Molecular identification of ahyperpolarization-activated channel in sea urchin sperm. Nature393:583–587,1998.
[54] Ludwig A, Zong X, Jeglitsch M, Hofmann F, Biel M. A family ofhyperpolarization-activated mammalian cation channels. Nature393:587–591,1998.
[55] Zagotta WN, Olivier NB, Black KD, Young EC, Olson R, Gouaux E. Structural basisfor modulation and agonist specificity of HCN pacemaker channels. Nature425:200–205,2003.
[56] Vargas G, Lucero MT. Modulation by PKA of the hyperpolarization-activated current(Ih) in cultured rat olfactory receptor neurons. J Membr Biol188:115–125,2002.
[57] DiFrancesco D. Characterization of single pacemaker channels in cardiac sino-atrialnode cells. Nature324:470–473,1986.
[58] Van Ginneken AC, Giles W. Voltage clamp measurements of thehyperpolarization-activated inward current I(f) in single cells from rabbit sino-atrialnode. J Physiol434:57–83,1991.
[59] Ho WK, Brown HF, Noble D. High selectivity of the i(f) channel to Na_and K_inrabbit isolated sinoatrial node cells. Pflu¨ gers Arch426:68–74,1994.
[60] Wollmuth LP, Hille B. Ionic selectivity of Ih channels of rod photoreceptors in tigersalamanders. J Gen Physiol100:749–765,1992.
[61] Ludwig A, Zong X, Jeglitsch M, Hofmann F, Biel M. A family ofhyperpolarization-activated mammalian cation channels. Nature393:587–591,1998.
[62] Tanaka E, Higashi H, Nishi S. Membrane properties of guinea pig cingulate corticalneurons in vitro. J Neurophysiol65:808–821,1991.
[63] Frace AM, Maruoka F, Noma A. External K_increases Na conductance of thehyperpolarization-activated current in rabbit cardiac pacemaker cells. Pflu¨ gers Arch421:97–99,1992.
[64] DiFrancesco D. A study of the ionic nature of the pace-maker current in calf Purkinjefibres. J Physiol314:377–393,1981.
[65] Frace AM, Maruoka F, Noma A. Control of the hyperpolarization-activated cationcurrent by external anions in rabbit sino-atrial node cells. J Physiol453:307–318,1992.
[66] Yu X, Chen XW, Zhou P, Yao L, Liu T, Zhang B, Li Y, Zheng H, Zheng LH, ZhangCX, Bruce I, Ge JB, Wang SQ, Hu ZA, Yu HG, Zhou Z. Calcium influx through Ifchannels in rat ventricular myocytes. Am J Physiol Cell Physiol292: C1147–C1155,2007.
[67] Yu X, Duan KL, Shang CF, Yu HG, Zhou Z. Calcium influx throughhyperpolarization-activated cation channels [I(h) channels] contributes toactivity-evoked neuronal secretion. Proc Natl Acad Sci USA101:1051–1056,2004.
[68] Kole MH, Hallermann S, Stuart GJ. Single Ih channels in pyramidal neuron dendrites:properties, distribution, and impact on action potential output. J Neurosci26:1677–1687,2006.
[69] Michels G, Er F, Khan I, Sudkamp M, Herzig S, Hoppe UC. Single-channel propertiessupport a potential contribution of hyperpolarization-activated cyclic nucleotide-gatedchannels and If to cardiac arrhythmias. Circulation111:399–404,2005.
[70] Poolos NP, Bullis JB, Roth MK. Modulation of h-channels in hippocampal pyramidalneurons by p38mitogen-activated protein kinase. J Neurosci26:7995–8003,2006.
[71] Michels G, Er F, Khan IF, Endres-Becker J, Brandt MC, Gassanov N, Johns DC, HoppeUC. K channel regulator KCR1suppresses heart rhythm by modulating the pacemakercurrent I(f). PLoS ONE3: e1511,2008.
[72] DiFrancesco D. Block and activation of the pace-maker channel in calf Purkinje fibres:effects of potassium, caesium and rubidium. J Physiol329:485–507,1982.
[73] Deal KK, England SK, Tamkun MM. Molecular physiology of cardiac potassiumchannels. Physiol Rev76:49–67,1996.
[74] Nerbonne JM, Kass RS. Molecular physiology of cardiac repolarization. Physiol Rev85:1205–1253,2005.
[75] Biel M, Michalakis S. Function and dysfunction of CNG channels: insights fromchannelopathies and mouse models. Mol Neurobiol35:266–277,2007.
[76] Yu FH, Yarov-Yarovoy V, Gutman GA, Catterall WA. Overview of molecularrelationships in the voltage-gated ion channel superfamily. Pharmacol Rev57:387–395,2005.
[77] Gauss R, Seifert R, Kaupp UB. Molecular identification of ahyperpolarization-activated channel in sea urchin sperm. Nature393:583–587,1998.
[78] Ishii TM, Takano M, Xie LH, Noma A, Ohmori H. Molecular characterization of thehyperpolarization-activated cation channel in rabbit heart sinoatrial node. J Biol Chem274:12835–12839,1999.
[79] Krieger J, Strobel J, Vogl A, Hanke W, Breer H. Identification of a cyclic nucleotide-and voltage-activated ion channel from insect antennae. Insect Biochem Mol Biol29:255–267,1999.
[80] Shi W, Wymore R, Yu H, Wu J, Wymore RT, Pan Z, Robinson RB, Dixon JE,McKinnon D, Cohen IS. Distribution and prevalence of hyperpolarization-activatedcation channel (HCN) mRNA expression in cardiac tissues. Circ Res85: e1–6,1999
[81] Jackson HA, Marshall CR, Accili EA. Evolution and structural diversification ofhyperpolarization-activated cyclic nucleotidegated channel genes. Physiol Gen29:231–245,2007.
[82] Gisselmann G, Marx T, Bobkov Y, Wetzel CH, Neuhaus EM, Ache BW, Hatt H.Molecular and functional characterization of an I(h)-channel from lobster olfactoryreceptor neurons. Eur J Neurosci21:1635–1647,2005.
[83] Marx T, Gisselmann G, Stortkuhl KF, Hovemann BT, Hatt H. Molecular cloning of aputative voltage-and cyclic nucleotide-gated ion channel present in the antennae andeyes of Drosophila melanogaster. Invert Neurosci4:55–63,1999.
[84] Galindo BE, Neill AT, Vacquier VD. A new hyperpolarizationactivated, cyclicnucleotide-gated channel from sea urchin sperm flagella. Biochem Biophys ResCommun334:96–101,2005.
[85] Altomare C, Terragni B, Brioschi C, Milanesi R, Pagliuca C,Viscomi C, Moroni A,Baruscotti M, DiFrancesco D. Heteromeric HCN1-HCN4channels: a comparison withnative pacemaker channels from the rabbit sinoatrial node. J Physiol549:347–359,2003.
[86] Chen S, Wang J, Siegelbaum SA. Properties of hyperpolarization-activated pacemakercurrent defined by coassembly of HCN1and HCN2subunits and basal modulation bycyclic nucleotide. J Gen Physiol117:491–504,2001.
[87] Er F, Larbig R, Ludwig A, Biel M, Hofmann F, Beuckelmann DJ, Hoppe UC.Dominant-negative suppression of HCN channels markedly reduces the nativepacemaker current I(f) and undermines spontaneous beating of neonatalcardiomyocytes. Circulation107:485–489,2003.
[88] Gisselmann G, Gamerschlag B, Sonnenfeld R, Marx T, Neuhaus EM, Wetzel CH, HattH. Variants of the Drosophila melanogaster Ih-channel are generated by differentsplicing. Insect Biochem Mol Biol35:505–514,2005.
[89] Gisselmann G, Wetzel CH, Warnstedt M, Hatt H. Functional characterization ofIh-channel splice variants from Apis mellifera. FEBS Lett575:99–104,2004.
[90] Ouyang Q, Goeritz M, Harris-Warrick RM. Panulirus interruptus Ih-channel gene PIIH:modification of channel properties by alternative splicing and role in rhythmic activity.J Neurophysiol97:3880–3892,2007.
[91] Kaupp UB, Seifert R. Molecular diversity of pacemaker ion channels. Annu RevPhysiol63:235–257,2001.
[92] DiFrancesco D, Ferroni A, Mazzanti M, Tromba C. Properties of thehyperpolarizing-activated current (if) in cells isolated from the rabbit sino-atrial node. JPhysiol377:61–88,1986.
[93] Ishii TM, Takano M, Ohmori H. Determinants of activation kinetics in mammalianhyperpolarization-activated cation channels. J Physiol537:93–100,2001.
[94] Stieber J, Stockl G, Herrmann S, Hassfurth B, Hofmann F. Functional expression of thehuman HCN3channel. J Biol Chem280:34635–34643,2005.
[95] Wainger BJ, DeGennaro M, Santoro B, Siegelbaum SA, Tibbs GR. Molecularmechanism of cAMP modulation of HCN pacemaker channels. Nature411:805–810,2001.
[96] Stieber J, Stockl G, Herrmann S, Hassfurth B, Hofmann F. Functional expression of thehuman HCN3channel. J Biol Chem280:34635–34643,2005.
[97] Chaplan SR, Guo HQ, Lee DH, Luo L, Liu C, Kuei C, VelumianAA, Butler MP,Brown SM, Dubin AE. Neuronal hyperpolarization-activated pacemaker channels driveneuropathic pain. J Neurosci23:1169–1178,2003.
[98] Mistrik P, Mader R, Michalakis S, Weidinger M, Pfeifer A, Biel M. The murine HCN3gene encodes a hyperpolarization-activated cation channel with slow kinetics andunique response to cyclic nucleotides. J Biol Chem280:27056–27061,2005.
[99] Hardel N, Harmel N, Zolles G, Fakler B, Klocker N. Recycling endosomes supplycardiac pacemaker channels for regulated surface expression. Cardiovasc Res79:52–60,2008.
[100] Hoshi T. Regulation of voltage dependence of the KAT1channel by intracellularfactors. J Gen Physiol105:309–328,1995.
[101] El-Kholy W, MacDonald PE, Fox JM, Bhattacharjee A, Xue T, Gao X, Zhang Y,Stieber J, Li RA, Tsushima RG, Wheeler MB. Hyperpolarization-activated cyclicnucleotide-gated channels in pancreatic beta-cells. Mol Endocrinol21:753–764,2007.
[102] Hisada T, Ordway RW, Kirber MT, Singer JJ, Walsh JV Jr.Hyperpolarization-activated cationic channels in smooth muscle cells are stretchsensitive. Pflu¨ gers Arch417:493–499,1991.
[103] McCloskey KD, Toland HM, Hollywood MA, Thornbury KD, McHale NG.Hyperpolarisation-activated inward current in isolated sheep mesenteric lymphaticsmooth muscle. J Physiol521:201–211,1999.
[104] Okabe K, Inoue Y, Kawarabayashi T, Kajiya H, Okamoto F, Soeda H. Physiologicalsignificance of hyperpolarization-activated inward currents (Ih) in smooth muscle cellsfrom the circular layers of pregnant rat myometrium. Pflu¨ gers Arch439:76–85,1999.
[105] Greenwood IA, Prestwich SA. Characteristics of hyperpolarization-activated cationcurrents in portal vein smooth muscle cells. Am J Physiol Cell Physiol282:C744–C753,2002.
[106] Xiao J, Nguyen TV, Ngui K, Strijbos PJ, Selmer IS, Neylon CB, Furness JB. Molecularand functional analysis of hyperpolarisation-activated nucleotide-gated (HCN) channelsin the enteric nervous system. Neuroscience129:603–614,2004.
[107] Greenwood IA, Prestwich SA. Characteristics of hyperpolarization-activated cationcurrents in portal vein smooth muscle cells. Am J Physiol Cell Physiol282:C744–C753,2002.
[108] Milligan CJ, Edwards IJ, Deuchars J. HCN1ion channel immunoreactivity in spinalcord and medulla oblongata. Brain Res1081:79–91,2006.
[109] Santoro B, Chen S, Luthi A, Pavlidis P, Shumyatsky GP, Tibbs GR, Siegelbaum SA.Molecular and functional heterogeneity of hyperpolarization-activated pacemakerchannels in the mouse CNS. J Neurosci20:5264–5275,2000
[110] Cangiano L, Gargini C, Della Santina L, Demontis GC, Cervetto L. High-pass filteringof input signals by the I(h) current in a non-spiking neuron, the retinal rod bipolar cell.PLoS ONE2: e1327,2007.
[111] Chevaleyre V, Castillo PE. Assessing the role of Ih channels in synaptic transmissionand mossy fiber LTP. Proc Natl Acad Sci USA99:9538–9543,2002.
[112] Moosmang S, Stieber J, Zong X, Biel M, Hofmann F, Ludwig A. Cellular expressionand functional characterization of four hyperpolarization-activated pacemaker channelsin cardiac and neuronal tissues. Eur J Biochem268:1646–1652,2001
[113] Marionneau C, Couette B, Liu J, Li H, Mangoni ME, Nargeot J, Lei M, Escande D,Demolombe S. Specific pattern of ionic channel gene expression associated withpacemaker activity in the mouse heart. J Physiol562:223–234,2005.
[114] Dobrzynski H, Nikolski VP, Sambelashvili AT, Greener ID, Yamamoto M, Boyett MR,Efimov IR. Site of origin and molecular substrate of atrioventricular junctional rhythmin the rabbit heart. Circ Res93:1102–1110,2003.
[115] Shi W, Yu H, Wu J, Zuckerman J, Wymore R. The distribution and prevalence of HCNisoforms in the canine heart and their relation to voltage dependence of If. Biophys J78:e353A,2000.
[116] Fernandez-Velasco M, Goren N, Benito G, Blanco-Rivero J, Bosca L, Delgado C.Regional distribution of hyperpolarizationactivated current (If) andhyperpolarization-activated cyclic nucleotide-gated channel mRNA expression inventricular cells from control and hypertrophied rat hearts. J Physiol553:395–405,2003.
[117] Seccareccia F, Pannozzo F, Dima F, Minoprio A, Menditto A, Lo Noce C, Giampaoli S.Heart rate as a predictor of mortality: the MATISS project. Am J Public Health91:1258–1263,2001.
[118] Doesch AO, Celik S, Ehlermann P, Frankenstein L, Zehelein J, Koch A, Katus HA,Dengler TJ. Heart rate reduction after heart transplantation with beta-blocker versus theselective If channel antagonist ivabradine. Transplantation84:988–996,2007.
[119] Sulfi S, Timmis AD. Ivabradine: the first selective sinus node I(f) channel inhibitor inthe treatment of stable angina. Int J Clin Pract60:222–228,2006.
[120] Bucchi A, Baruscotti M, DiFrancesco D. Current-dependent block of rabbit sino-atrialnode I(f) channels by ivabradine. J Gen Physiol120:1–13,2002.
[121] Thollon C, Bedut S, Villeneuve N, Coge F, Piffard L, Guillaumin JP, Brunel-JacqueminC, Chomarat P, Boutin JA, Peglion JL, Vilaine JP. Use-dependent inhibition of hHCN4by ivabradine and relationship with reduction in pacemaker activity. Br J Pharmacol150:37–46,2007.
[122] Stieber J, Wieland K, Stockl G, Ludwig A, Hofmann F. Bradycardic and proarrhythmicproperties of sinus node inhibitors. Mol Pharmacol69:1328–1337,2006.
[123] DiFrancesco D. Some properties of the UL-FS49block of thehyperpolarization-activated current [i(f)] in sino-atrial node myocytes. Pflu¨ gers Arch427:64–70,1994.
[124] BoSmith RE, Briggs I, Sturgess NC. Inhibitory actions of ZENECA ZD7288onwhole-cell hyperpolarization activated inward current (If) in guinea-pig dissociatedsinoatrial node cells. Br J Pharmacol110:343–349,1993.
[125] Snyders DJ, Van Bogaert PP. Alinidine modifies the pacemaker current in sheepPurkinje fibers. Pflu¨ gers Arch410:83–91,1987.
[126] Knaus A, Zong X, Beetz N, Jahns R, Lohse MJ, Biel M, Hein L. Direct inhibition ofcardiac hyperpolarization-activated cyclic nucleotide-gated pacemaker channels byclonidine. Circulation115:872–880,2007.
[127] Cervetto L, Demontis GC, Gargini C. Cellular mechanisms underlying thepharmacological induction of phosphenes. Br J Pharmacol150:383–390,2007.
[128] Sanchez-Alonso JL, Halliwell JV, Colino A. ZD7288inhibits T-type calcium currentin rat hippocampal pyramidal cells. Neurosci Lett439:275–280,2008.
[1] Cajal SR. Sur les ganglions et plexus nerveux de l'intestin. C R Seances Soc Biol Fil45:217–223,1893.
[2] Cajal SR. Histologie du Système Nerveux de l'Homme et des Vertébrés. Paris: Maloine,1911.
[3] Thuneberg L. One hundred years of interstitial cells of Cajal. Microsc Res Tech47:223–238,1999.
[4] Sanders KM. A case for interstitial cells of Cajal as pacemakers and mediators ofneurotransmission in the gastrointestinal tract. Gastroenterology111:492–515,1996.
[5] Rumessen JJ and Thuneberg L. Pacemaker cells in the gastrointestinal tract: interstitialcells of Cajal. Scand J Gastroenterol216(Suppl):82–94,1996.
[6] Cousins HM et al. Electrical coupling between the myenteric interstitial cells of Cajal andadjacent muscle layers in the guinea-pig gastric antrum. J Physiol550:829–84,2003.
[7] Ward SM and Sanders KM. Interstitial cells of Cajal: primary targets of enteric motorinnervation. Anat Rec262:125–135,2001.
[8] Horowitz B et al. Cellular and molecular basis for electrical rhythmicity ingastrointestinal muscles. Annu Rev Physiol61:19–43,1999.
[9] Komuro T et al. Ultrastructural characterization of the interstitial cells of Cajal. ArchHistol Cytol62:295–316,1999.
[10] Ward SM et al. Propagation of slow waves requires IP3receptors and mitochondrial Ca2+uptake in canine colonic muscles. J Physiol549:207–218,2003.
[11] Koh SD et al. Conductances responsible for slow wave generation and propagation ininterstitial cells of Cajal. Curr Opin Pharmacol3:579–582,2003.
[12] Mikkelsen HB et al. Action potential generation, Kit receptor immunohistochemistry andmorphology of steel-Dickie (Sl/Sld) mutant mouse small intestine. NeurogastroenterolMotil10:11–26,1998.
[13] Sanders KM et al. Physiology and pathophysiology of the interstitial cells of Cajal: frombench to bedside. IV. Genetic and animal models of GI motility disorders caused by lossof interstitial cells of Cajal. Am J Physiol Gastrointest Liver Physiol282:747–756,2002.
[14] Smet PJ et al. Distribution of nitric oxide synthase-immunoreactive nerves andidentification of the cellular targets of nitric oxide in guinea-pig and human urinarybladder by cGMP immunohistochemistry. Neuroscience71:337–348,1996.
[15] Sergeant GP et al. Specialised pacemaking cells in the rabbit urethra. J Physiol526:359–366,2000.
[16] Sergeant GP et al. Spontaneous Ca2+activated Cl-currents in isolated urethral smoothmuscle cells. J Urol166:1161–1166,2001.
[17] Hollywood MA et al. Activation of Ca2+-activated Cl-current by depolarizing steps inrabbit urethral interstitial cells. Am J Physiol Cell Physiol285:327–333,2003.
[18] Johnston L et al. Calcium oscillations in interstitial cells of the rabbit urethra. J Physiol565:449–461,2005.
[19] McCloskey KD and Gurney AM. Kit positive cells in the guinea pig bladder. J Urol168:832–836(2002)
[20] Davidson RA and McCloskey KD. Morphology and localization of interstitial cells in theguinea-pig bladder: structural relationships with smooth muscle and neurons. J Urol173:1385–1390,2005.
[21] Hashitani H et al. Role of interstitial cells and gap junctions in the transmission ofspontaneous Ca2+signals in detrusor smooth muscles of the guinea-pig urinary bladder. JPhysiol559:567–581,2004.
[22] Sui GP et al. Gap junctions and connexin expression in human suburothelial interstitialcells. BJU Int90:118–129,2002.
[23] Gosling JA and Dixon JS. Structural evidence in support of an urinary tract pacemaker. BrJ Urol44:550–560,1972.
[24] Klemm MF et al. Identification of the cells underlying pacemaker activity in theguinea-pig upper urinary tract. J Physiol519:867–884,1999.
[25] Pezzone MA et al. Identification of c-kit-positive cells in the mouse ureter: the interstitialcells of Cajal of the urinary tract. Am J Physiol Renal Physiol284:925–929,2003.
[26] Metzger R et al. Cajal-like cells in the human upper urinary tract. J Urol172:769–772,2004.
[27] Solari V et al. Altered expression of interstitial cells of Cajal in congenital ureteropelvicjunction obstruction. J Urol170:2420–2422,2003.
[28] Exintaris B et al. Spontaneous slow wave and contractile activity of the guinea pigprostate. J Urol168:315–322,2002.
[29] Van der Aa F et al. Interstitial cells in the human prostate: a new therapeutic target?Prostate56:250–255,2003.
[30] Hashitani H and Suzuki H. Identification of interstitial cells of Cajal in corporal tissues ofthe guinea-pig penis. Br J Pharmacol141:199–204,2004.
[31] Burton LD et al. P2X2receptor expression by interstitial cells of Cajal in vas deferensimplicated in semen emission. Auton Neurosci84:147–161,2000.
[32] Drake MJ et al. Morphology, phenotype and ultrastructure of fibroblastic cells fromnormal and neuropathic human detrusor: absence of myofibroblast characteristics. J Urol169:1573–1576,2003.
[33] Wu C et al. Purinergic regulation of guinea pig suburothelial myofibroblasts. J Physiol559:231–243,2004.
[34] Wiseman OJ et al. The role of the human bladder lamina propria myofibroblast. BJU Int91:89–93,2003.
[35] Powell DW et al. Myofibroblasts. I. Paracrine cells important in health and disease. Am JPhysiol277:1–9,1999.
[36] Hashitani H et al. Properties of spontaneous depolarizations in circular smooth musclecells of rabbit urethra. Br J Pharmacol118:1627–1632,1996.
[37] Cotton KD et al. Ca2+current and Ca2+-activated chloride current in isolated smoothmuscle cells of the sheep urethra. J Physiol505:121–131,1997.
[38] Turner WH and Brading AF. Smooth muscle of the bladder in the normal and the diseasedstate: pathophysiology, diagnosis and treatment. Pharmacol Ther75:77–110,1997.
[39] Daniel EE et al. Structural bases for neural and myogenic control of human detrusormuscle. Can J Physiol Pharmacol61:1247–1273,1983.
[40] Bramich NJ and Brading AF. Electrical properties of smooth muscle in the guinea-pigurinary bladder. J Physiol492:185–198,1996.
[41] Hanani M and Brading AF. Electrical coupling in smooth muscles. Is it universal? J BasicClin Physiol Pharmacol11:321–330,2000.
[42] Hashitani H and Brading AF. Electrical properties of detrusor smooth muscles from thepig and human urinary bladder. Br J Pharmacol140:146–158,2003.
[43] Hashitani H and Brading AF. Ionic basis for the regulation of spontaneous excitation indetrusor smooth muscle cells of the guinea-pig urinary bladder. Br J Pharmacol140:159–169,2003.
[44] Hashitani H et al. Origin and propagation of spontaneous excitation in smooth muscle ofthe guinea-pig urinary bladder. J Physiol530:273–286,2001.
[45] Kubota Y et al. Investigation of the effect of the c-kit inhibitor Glivec on isolatedguinea-pig detrusor preparations. Auton Neurosci115:64–73,2004.
[46] Biers SM. Novel pharmological treatments for detrusor overactivity [thesis]. Oxford:Oxford University,2005.
[47] Gillespie JI. The autonomous bladder: a view of the origin of bladder overactivity andsensory urge. BJU Int93:478–483,2004.
[48] De Ridder D et al. Nitric oxide synthase expression in neurogenic bladder disease: a pilotstudy. Acta Neurol Belg99:57–60,1999.
[49] Moon A. Influence of nitric oxide signalling pathways on pre-contracted human detrusorsmooth muscle in vitro. BJU Int89:942–949,2002.
[50] Ost D et al. Topography of the vanilloid receptor in the human bladder: more than just thenerve fibers. J Urol168:293–297,2002.
[51] Fry CH et al. Cell biology. In Incontinence:3rd International Consultation onIncontinence,313–362(Eds Abrams P et al.). Plymouth: Health Publication Ltd,2005.
[52] Kubota Y et al.: The effects of imatinib mesylate (Glivec) as a c-kit tyrosine kinaseinhibitor in the guinea-pig urinary bladder. Neurourol Urodyn,25:205-210,2006.
[53] Piotrowska AP et al. Interstitial cells of Cajal in the human normal urinary bladder and inthe bladder of patients with megacystis-microcolon intestinal hypoperistalsis syndrome.BJU Int94:143–146,2004.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |