摘要
糖尿病(diabetes mellitus,DM)在世界广泛流行,糖尿病神经病变(diabeticl neuropathy,DN)是常见的糖尿病慢性并发症。UKPDS对糖尿病神经病变流行病学的研究发现,超过11%的患者在糖尿病确诊的同时就已经存在明显的糖尿病神经病变,病程大于12年的患者中71%的男性以及51%的女性已经存在明显的临床期糖尿病神经病变。而且糖尿病神经病变累计多个器官和系统,表现多样,严重程度不一,即是糖尿病患者致残、致死的致死的重要原因,又是影响血糖稳定的重要因素,同时也是促进其他糖尿病慢性并发症发生、发展的原因之一。
糖尿病周围神经病变( diabetic peripheral neuropathy,DPN )是糖尿病最常见的慢性并发症之一,发生最早,文献报道其发生率为10%～90%不等。DPN可累及感觉神经、运动神经和自主神经,但以感觉神经最为常见。不但引起糖尿病患者的病死率和致残率升高,而且带来了复杂的护理、医疗问题,也是造成糖尿病患者反复住院的主要原因。
糖尿病周围神经病变发病机制尚未完全明了,但已知并非单一因素所致。近年来糖尿病并发症的临床及实验研究显示:可能与多种因素有关,例如:糖基化终末产物增加、氧化应激、多元醇通路、免疫因素、神经生长因子、遗传易感性等等。
通过近些年的研究,发现脂代谢异常和炎症常在胰岛素抵抗、2型糖尿病、糖尿病并发症发生、发展起着重要的作用。在2001年在美国糖尿病协会大会上McGarry提出“脂毒性”学说,认为脂代谢障碍为糖尿病及其并发症的原发性病理生理改变。在2005年在美国糖尿病协会会议上,糖尿病“炎症学说”也得到了国内外内分泌学者的广泛认可。但是目前对于脂代谢异常和炎症与糖尿病周围神经病变的研究很少。
本课题试图从游离脂肪酸-炎症-糖尿病周围神经病变的角度探讨2型糖尿病周围神经病变的发生机制。
课题第一、第二部分为临床研究,首先搜集临床2型糖尿病周围神经病变患者的资料,采用Logistic多元回归分析,探讨2型糖尿病周围神经病变的危险因素,以及FFA、炎症因子TNF-α、IL-6与周围神经病变的关系。
第三、第四部分为动物实验研究,通过给予大鼠高脂饮食喂养8周诱导出胰岛素抵抗,然后注射小剂量STZ造成血糖轻度升高,建立具有高游离脂肪酸特征的2型糖尿病大鼠模型,继续喂养高脂饮食20周后出现周围神经病变,从而建立糖尿病周围神经病变模型。
在建立的糖尿病周围神经病变大鼠模型基础上,检测血游离脂肪酸水平以及坐骨神经上核转录因子NF-κB以及炎症因子TNF-α、IL-6的表达,明确糖尿病周围神经病变时坐骨神经NF-κB以及TNF-α、IL-6水平的变化,同时有一组大鼠进行非诺贝特干预。观察干预后血游离脂肪酸下降,会对糖尿病周围神经病产生什么样的影响。从而探讨糖尿病周围神经病变的发生机制及其干预措施,为临床糖尿病周围神经病变预防以及治疗研究提供提供一个方向。本实验包括以下4各部分:
第一部分:2型糖尿病周围神经病变危险因素分析
目的:通过对我院547例2型糖尿病住院患者进行Logistic多元回归分析,探讨2型糖尿病周围神经病变的危险因素。
方法:回顾性分析选择本院2007年1月至2007年12月,临床确诊为2型糖尿病的患者547例,男304例,女243例,年龄28-78岁,平均57.34岁。根据双下肢肌电电生理检查分为DPN组315例,非DPN组(NDPN组)232例。每组均检测血压、身高、体重、腰围、臀围,计算体质量指数、糖化血红蛋白(HbA1c)、尿A/C、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、空腹以及2小时血糖、空腹和2小时胰岛素及C肽。两组间比较采用t检验;两组间计量资料采用X2检验;采用Logistic多元回归分析各危险因素与糖尿病周围神经病变的关系。
结果:1、血压、年龄、病程、体质量指数与周围神经病变的关系:合并周围神经病变组的年龄、病程、收缩压、舒张压与非周围神经病变组比较,差异有显著性;而体重指数两组比较差异无显著性。2、OGTT试验空腹以及2h血糖、胰岛素、C肽与周围神经病变的关系:在周围神经病变组,OGTT试验空腹血糖、2h血糖与非周围神经病变组比较,差异有显著性。3、血脂与糖尿病周围神经病变的关系:TG、TC、极低密度脂蛋白(VLDL)、低密度脂蛋白(LDL)在周围神经病变组高于非神经病变组,差异有显著性;高密度脂蛋白两组比较无统计学差异。4、糖化血红蛋白、尿A/C与周围神经病变的关系:周围神经病变组糖化血红蛋白、尿A/C均高于非周围神经病变组,差异有显著性。5、与糖尿病周围神经病变相关危险因素的Logistic多元回归分析:单因素分析表明,年龄、性别、收缩压、舒张压、糖化血红蛋白、尿A/C、TG、TC、LDL、VLDL、OGTT试验空腹血糖、胰岛素、C肽以及2小时血糖、胰岛素、C肽两组间比较有统计学差异(P值均<0.05或0.01)。再将上述各指标进入Logistic多元回归分析,结果表明年龄、病程、尿A/C、TG、2小时血糖、空腹及2小时胰岛素、空腹及2小时C肽有统计学意义,为糖尿病周围神经病变的危险因素。
结论:1、糖尿病周围神经病变组与非周围神经病变组的各个指标进行单因素分析,结果显示:年龄、病程、性别、收缩压、舒张压、糖化血红蛋白、尿A/C、TG、TC、LDL、VLDL、空腹血糖、胰岛素、C肽以及OGTT 2小时血糖、胰岛素、C肽在两组之间具有统计学差异。2、Logistic多元回归分析,结果表明年龄、病程、尿A/C、TG、VLDL、空腹及2小时胰岛素、空腹及2小时C肽、空腹及2小时血糖是有统计学意义的危险因素。
第二部分:血清游离脂肪酸、炎症因子与2型糖尿病周围神经病变的相关分析
目的:164例糖尿病患者分为周围神经病变组和非周围神经病变组,观察两组患者血清游离脂肪酸、炎症因子IL-6、TNF-α的水平,探讨游离脂肪酸、IL-6、TNF-α与糖尿病周围神经病变的关系。
方法:选择本院2008年3月至2008年9月,临床确诊为2型糖尿病的患者92例,男50例,女42例,年龄35-69岁,平均56.5岁。根据双下肢肌电电生理检查分为DPN组40例,非DPN组(NDPN组)52例。另选同期健康体检者40例作为健康对照组(NC组),男20例,女20例,平均年龄53.2。每组均检测血压、身高、体重、腰围、臀围,计算体质量指数、糖化血红蛋白(HbA1c)、尿A/C、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、空腹以及2小时血糖、空腹和2小时胰岛素及C肽。SPSS 11.5统计软件进行统计学处理,计量资料用均数±标准差(x±s)表示,两组间比较采用t检验。两组间计量资料采用X2检验。两变量的相关采用简单相关分析,糖尿病周围神经病变危险因素分析采用Logistic多元回归。所有数据进行方差齐性检验及正态性分布检验,非正态分布的数据转换成正态分布数据后进行统计分析。以P<0.05为差异有显著性。
结果:1、对各组数据行正态分布性及方差齐性检验,DPN组、非DPN组、T2DM组以及NC组的性别、年龄均匹配,各组间具有可比性。2、T2DM组与正常对照组比较:DBP、BMI、TG升高(P <0.05),SBP、FPG、HbAlc显著升高(P<0.01),HDL-C显著降低(P<0.01)。3、DPN组与非DPN组比较:病程、SBP、FPG、TG升高(P<0.05),HbAlc、FIns显著升高(P<0.01) 4、各组血清FFA水平的比较:与对照组(NC)相比,T2DM组患者血清FFA含量均显著升高(P<0.0l),与非DPN组比较,DPN组血清FFA含量显著升高(P<0.0l)。5、各组血清TNF-α水平的比较:与对照组(NC)相比,T2DM组患者血清TNF-α含量显著升高(P<0.01),与非DPN组比较,DPN组血清TNF-α含量显著升高(P<0.0l)。6、各组血清IL-6水平的比较:与对照组(NC)相比,T2DM组患者血清IL-6含量显著升高(P<0.01),与非DPN组比较,DPN组血清IL-6含量显著升高(P<0.0l)。7、糖尿病周围神经病变危险因素分析:病程、尿A/C、HbAlc、TNF-α、FFA、IL-6进入回归方程。8、相关分析表明:炎症因子TNF-α、IL-6与血游离脂肪酸水平呈正相关。
结论:1、糖尿病周围神经病变组血清游离脂肪酸水平高于非周围神病变组及对照组,有统计学意义。Logistic多元回归分析表明,血游离脂肪酸是糖尿病周围神经病变的危险因素。2、糖尿病周围神经病变组炎症因子TNF-α、IL-6水平高于糖尿病非周围神经病变组,有统计学意义。Logistic多元回归分析表明,炎症因子TNF-α、IL-6是糖尿病周围神经病变的危险因素。3、相关分析表明,炎症因子TNF-α、IL-6水平与血清游离脂肪酸水平呈正相关。
第三部分:2型糖尿病大鼠血清游离脂肪酸与周围神经病变的关系及非诺贝特的干预作用
目的:探讨2型糖尿病周围神经病变大鼠,血清游离脂肪酸升高与糖尿病周围神经病变的关系,以及非诺贝特的干预作用。
方法:体重280-310g的雄性Wistar大鼠40只随机分为2组:对照组(NC)10只、高脂组(HF)30只,对照组给予基础饲料,热量组成:碳水化合物65.5%,脂肪10.3%,,蛋白质24.2%,总热量为348kcal/100g;高脂组给予高脂饲料,其热量组成:碳水化合物20.1%,脂肪59.8 %,蛋白质20.1%,总热量为501kcal/100g;每4周称重一次。喂养8周后,高脂组大鼠注射STZ,按照30mg/kg注射(配成1%的PH 4.2的枸橼酸缓冲液),注射后4周检测鼠尾空腹血糖,选取血糖大于7.0mmol/L的大鼠23只糖尿病模型组,再随机分为2组,糖尿病组(DM组)11只以及糖尿病非诺贝特干预组(DMF组)12只,每组均3%戊巴比妥麻醉后心脏采血,取血清进行TC、TG、FFA检测,TC、TG采用自动生化分析仪检测,FFA采用铜比色法检测。每组均继续喂以高脂饮食,DMF组给予非诺贝特30mg/kg灌胃,DM组给予等量的生理盐水灌胃。继续喂养,每2周麻醉下各组进行双下肢胫神经电生理检查以及热痛阈、机械痛阈检查,至胫神经电生理出现异常,与对照组有统计学差异时,实验结束(此时为第35周)。实验结束后颈动脉放血处死,取血进行一般生化检验,立即取下坐骨神经放入液氮,并转移到-70℃低温冰箱保存。
结果:1、高脂饮食喂养8周后,HF组大鼠的体重、血糖、INS、TC、TG、FFA较NC组大鼠升高,有统计学差异(P<0.05或P<0.01)。STZ注射4周后,DPN组以及DPNF组大鼠的体重、INS与NC组大鼠比较无统计学差异(P>0.05);血糖、TC、TG、FFA较NC组大鼠升高,有统计学差异(P<0.05或P<0.01)。实验结束第32周时,DMF组的体重较DM组下降(P<0.01),DMF组的血糖、胰岛素较DN组降低,但无统计学差异(P>0.05),DMF组的TG、FFA较DM组有明显下降,有统计学差异(P<0.05或P<0.01)。2、STZ注射4周后,NC组、DM组以及DMF组的胫神经传导速度、潜伏期,热痛阈、机械痛阈数据无统计学差异(P>0.05);实验结束第32周,NC组、DM组以及DMF组的胫神经传导速度、潜伏期,热痛阈、机械痛阈有统计学差异(P<0.05或P<0.01)。3、电镜下可以看到,糖尿病周围神经病变组神经,髓鞘的髓板分离,轴突闭锁,而非诺贝特干预组病变程度减轻。4、相关分析表明:血游离脂肪酸与胫神经传导速度、潜伏期呈负相关。
结论:1、大鼠给予高脂饮食喂养8周,产生胰岛素抵抗,再注射小剂量STZ,血糖轻度升高,建立2型糖尿病大鼠模型,在此基础上继续喂养24周,出现坐骨神经传导速度减慢,潜伏期延长,以及神经的病理损害,从而建立了2型糖尿病大鼠周围神经病变模型。2、糖尿病周围神经病变组大鼠血清游离脂肪酸水平高于对照组,并且与神经传导速度的下降、潜伏期的延长相关,说明游离脂肪酸与糖尿病周围神经病变发生、发展有关。2、非诺贝特干预后糖尿病大鼠的血清游离脂肪酸水平下降,神经传导速度以及潜伏期改善,神经的病理损害减轻,进一步说明,血游离脂肪酸与周围神经病变相关。
第四部分:2型糖尿病大鼠坐骨神经NF-κB、TNF-α、IL-6表达及非诺贝特的干预作用
目的:探讨2型糖尿病周围神经病变大鼠坐骨神经NF-κB、TNF-α、IL-6蛋白以及mRNA的表达,以及非诺贝特的干预作用。
方法:动物分组及标本取得同第三部分。坐骨神经NF-κB、TNF-α、IL-6的mRNA表达采用半定量PCR技术,NF-κB、TNF-α、IL-6的蛋白表达用Western-blot分析。
结果:1、试验结束第32周时,与正常对照组相比,糖尿病神经病变组大鼠坐骨神经TNF-α、IL-6和NF-κB mRNA表达明显增高,差异有统计学意义(P<0.01);微粒化非诺贝特干预后,TNF-α、IL-6和NF-κB mRNA表达降低,与糖尿病神经病变组相比差异有显著性(P<0.05)。2、试验结束第32周时,与正常对照组相比,糖尿病神经病变组坐骨神经TNF-α、IL-6和NF-κB蛋白表达明显增高,差异有统计学意义(P<0.01);微粒化非诺贝特干预后,TNF-α、IL-6和NF-κB mRNA表达降低,与糖尿病神经病变组相比差异有显著性(P<0.05)3、相关分析结果表明:1)、TNF-α和IL-6蛋白的表达与NF-κB蛋白表达相关(r=-0.454和r=-0.324,P<0.01)。2)、NF-κB蛋白表达与游离脂肪酸相关(r=-0.379,P<0.01)。
结论:1、糖尿病周围神经病变组大鼠NF-κB、TNF-α、IL-6蛋白以及mRNA表达高于DM组,相关分析表明NF-κB、TNF-α、IL-6蛋白以及mRNA表达与胫神经传导速度、潜伏期相关,说明糖尿病神经病变可能与炎症因子的增高有关;2、DMF组大鼠的NF-κB、TNF-α、IL-6蛋白以及mRNA表达较DM组减少,进一步说明NF-κB、TNF-α、IL-6与糖尿病神经病变有关;3、NF-κB、TNF-α、IL-6蛋白以及mRNA与血游离脂肪酸相关分析表明,NF-κB、TNF-α、IL-6蛋白以及mRNA表达与游离脂肪酸相关。
A significant increase in type 2 diabetes mellitus can be demonstrated from all epidemiological studies.Diatebic neuropathy (DN) is one of the most frequent and troublesome complications of diabetes mellitus. In the U.K.Prospective Diabetes Study(UKPDS),over 11% of patients had diabetic neuropathy in the time of diagnosis of type 2 diabetes.At 12 years,thers were obverous diabetic neuropathy in 71% of men patients and 51% of women patients. It is the major reason for morbidity and mortality among diabetic patients.
Diabetic peripheral neuropathy(DPN) is the most common chronic complication of diabetes,accourting for substantial morbidity and mortality and resulting in huge health care costs.There are varied clinical presentations of DPN with involvement of proximal or distal peripheral sensory and motor nerves,as well as autonomic nerves.
Although there has been significant progress in the understanding of the clinical aspects of these conditions, it is difficult to answer the pathogenic mechanism of diabetic neuropathies.In the past few years,animal and clinic studies reveled that pathogenesis of diabetic neuropathy has multifactorial causes, such as:non-enzymatic glycation of proteins ,oxidative stress, the polyol pathway, immune mechanisms, neurotrophic growth factor ,genetic susceptibility.
In the recent years studies,it is found that dyslipidaemia and inflammation are important in the devolpment of insulin resistant,diabetes and complations of diabetes.In 2002,Mcgarry belive that dysregulation of fatty acid metabolism is the etiology of type 2 diabetes,and there is increasing evidence that low-grade inflammation is closely involved in the pathogenesis of type 2 diabetes and associated complications.But the relationship between dyslipidaemia、inflammation and diabetic peripheral neuropathy is unkown。
In our study,the first and second part are clinic research。By logistic regression analysis, to study the risk factors in the patients with type 2 diabetic peripheral neuropathy and relation between FFA、TNF-α、IL-6 and diabetic peripheral neuropathy.
In the third and forth part of reaserch, Female Wistar rats were fed with high-fat diet to induce insulin resistance.Hyperglycemia was developed by intraperitoned injection in these rats with 30mg/kg streptozotocin(STZ)after 8 weeks.The rats were accepted as diabetic in the light of their blood glucose exceeded 7.0mmol/L after 1 month of STZ injection.The serum FFA is high in these rats and continue to feed with the high-fat diets.Then, the model rats were divided into two groups: diabetic peripheral neuropathy group(DPN group) and treatment group(the rats were fed with fenofibrate 30mg/kg.d)(DPNFgroup).
We explore the possible relation between FFA、inflammation and diabetic peripheral neuropathy,and the effect of treatment with fenofibrate. To providing a new study direction of improving diabetic peripheral neuropathy. The paper contains four parts below:
Part one: Risk factors for diabetic peripheral neuropathy in type 2 diabetes mellitus patients
Objective: To study the risk factors in the patients with type 2 diabetic peripheral neuropathy.
Methods: 547 type 2 diabetic patients were tested for the nerve conduction velocities. The patients were divided into diabetic peripheral neuropathy group and non-diabetic peripheral neuropathy group. Blood pressure, triglycerides (TG), total cholesterol (TC), HDL-C, LDL-C, body mass index (BMI), glycosylated hemoglobin (HbA1c), insulin, C peptide and urinary albumin/creatinine (A/C) were measured for all patients. All the risk factors were included in the statistical analysis.
Results:Duration of diabetes, age, fasting plasma glucose,2-hour plasma glucose, TG, TC, urinary A/C and HbA1c in diabetic peripheral neuropathy group were significantly higher than that in non-diabetic peripheral neuropathy group(p<0.05 or p<0.01). The level of fasting insulin and plasma C peptide ,2-hour insulin and plasma C peptide were significantly lower than that in non-diabetic peripheral neuropathy group(p<0.05 or p<0.01).
Conclusions: By logistic regression analysis, it was found that the significant risk factors of diabetic peripheral neuropathy in type 2 diabetic patients were age, duration of diabetes,HbA1c, urinary A/C, fasting and 2-hour glucose、C peptide and insulin.
Part two: The relation between FFA、TNF-α、IL-6 and diabetic peripheral neuropathy in type 2 diabetes mellitus patients
Objective: 92 type 2 diabetic patients were divided into diabetic peripheral neuropathy group and non-diabetic peripheral neuropathy group. Serum FFA、TNF-α、IL-6 were measured for all patients and analysis the relationship between FFA、TNF-α、IL-6 and diabetic peripheral neuropathy.
Methods: According to the 1997 ADA criteria for DM diagnosis and the nerve conduction velocities, 92 type 2 diabetic patients were divided into diabetic peripheral neuropathy group (DPN group) and non-diabetic peripheral neuropathy group(NDPN group). Blood pressure, triglycerides (TG), total cholesterol (TC), HDL-C, LDL-C, body mass index (BMI), glycosylated hemoglobin (HbA1c), insulin, C peptide and urinary albumin/creatinine (A/C) ,serum FFA ,TNF-αand IL-6 were measured for all patients. All the risk factors were included in the statistical analysis.
Results: 1、Compared with NC group, the DBP、BMI、SBP、FPG、HbAlc、Fins、TG、LDL-C were higher in the DPN group and NDPN group(p<0.05 or p<0.01); the HDL-c was lower in the DPN group and NDPN group( p<0.01)。2、Compared with NDPN group, duration、SBP, DBP、FPG、HbAlc、Fins、TG、LDL-C were higher in the DPN group(P<0.05P<0.01).3、Compared with NC group,serum FFA TNF-αand IL-6 were higher in the DPN group and NDPN group(p<0.05 or p<0.01).4、Compared with NDPN group,serum FFA TNF-αand IL-6 were higher in the DPN group (p<0.05).5、By logistic regression analysis,with or without diabetic peripheral neuropathy as a dependent variable and with SBP,DBP、HbAlc、urinary A/C、Fins、FBG、TG、LDL-C、TNF-α、FFA、IL-6 as independent variable,finally duration、urinary A/C、HbAlc、HoMA-IR、TNF-α、FFA、IL-6 entered the equations.6、Serun TNF-αand IL-6 had a positive correlation with serum FFA.
Conclusions: The level of serum FFA、TNF-αand IL-6 of DPN group were significantly increased Compared with NC group and NDPN group. By logistic regression analysis suggests that serum FFA、TNF-αand IL-6 are the risk factors of diabetic peripheral neuropathy. Serum FFA have positive correlation with serum.TNF-α、IL-6,
Part three: Relation between serun FFA and diabetic peripheral neuropathy in type 2 diabetes rats and fenofibrate treatment.
Objective: To set up rat model of type 2 diabetes peripheral neuropathy and observe the correlation of serum FFA and peripheral neuropathy
Methods: Male Wistar rats weighed 300g were divided into normal control control (NC) group (n=10), high-fat diet (HF) group (n=30).The rats in control group were fed with a regular low fatty acids diet containing 10.3% fat, 24.2% protein, and 65.5% carbohydrate as percentage of total calories. The rats in high-fat diet group were fed regular diets mixed with 30% lard, containing 59.8% fat, 20.1% protein and 20.1% carbohydrate as a percentage of total calories. The rats in high-fat diet group were injected by intraperitoned with 30mg/kg streptozotocin(STZ)after 8 weeks.The rats were accepted as diabetic in the light of their fasting blood glucose exceeded 7.0mmol/L after 4 weeks of STZ injection.Total 23 rats’fasting blood glucose exceeded 7.0mmol/L ,and were randomly devided into diabetic peripheral neuropathy (DPN) group (N=11)and fenofibrate treatment (DPNF) group (N=12). The twe groups rats were continue to feed with the high-fat diets.The rats in DPNF group were given with fenofibrate 30mg/kg.d through intragastric administration once a day.
The body weights were determined every two weeks for 32 weeks. The electrophysiology was examined every four weeks.The blood sample was collected by cardiac puncture after rats were anesthetized with diethyl ether for the biochemical analysis.At the end of 32 week, the rats were killed with phenobarbital sodium, and sciatic nerve were taken out freeze-clamped with copper clamps precooled in liquid N2 and were stored in -70℃refrigerator.
Results: 1、After 8 weeks of fed with high-fat diet,compared with NC group, the bodyweight、FBG、FINS、TC、TG、FFA were higher in HF group(P<0.05 or P<0.01). After 4 weeks of STZ injection, compared with NC group,the body weight and Fins were sinple(P>0.05) ,and FBG、TC、TG、FFA were higher(P<0.05或P<0.01)in the HF group.2、At the end of 32 weeks, compered with DPN group , BG、TG、FFA were lower in DPNF group(P<0.05或P<0.01).The FBG and Fins were lower than DPNF group,but not signifecient(P>0.05).3、After 4 weeks of STZ injection, tibial nerve conduction velocity,latency period、withdrawa mechanical threshold and withdrawal thermal latency were not signifecient(P>0.05).At the end of 32 weeks, compered with NC group, tibial nerve conduction velocity lower,latency period longer、withdrawa mechanical threshold and withdrawal thermal latency higher in DPN group(P<0.05或P<0.01). Compered with DPN group, tibial nerve conduction velocity faster,latency period shorter、withdrawa mechanical threshold and withdrawal thermal latency lower in DPNF group(P<0.05或P<0.01).4、With electron microscope, lamina medullares of myelin sheath was chorisis, neurite was atresia in DPN group. But pathological changes were abatement in DPNF group.5、Serum FFA has a positive correlation with latency period and has a negative correlation with tibial nerve conduction velocity.
Conclusions: 1、After fed with high-fat diet after 8 weeks,insulin resistance developed in rats。These rats were intraperitoned injected with a low doze of STZ. After 4 weeks of STZ injection,fasting blood glucose and serm insuin was higher than NC group,so the rat model of type 2 diabetes mellitus was set up .The serum FFA was higher in the rat model. These rats continued to fed with high-fat diet,and diabetic peripheral neuropathy developed at 32th week. 2、Correlation analyses suggested that serum FFA associated with tibial nerve conduction velocity、latency period shorter、withdrawa mechanical threshold and withdrawal thermal latency lower。3、After treated with fenofibrate,serum FFA lowered and pathology damage of sciatic nerve improved,so that indicated serum FFA has a correlation with diabetic peripheral neuropathy.
Part four: The expression of NF-κB、TNF-α、IL-6 in sciatic nerve in rats of type 2 diabetic peripheral neuropathy and fenofibrate treatment.
Objective: To observe the expression of NF-κB、TNF-α、IL-6 in sciatic nerve in rats of type 2 diabetic peripheral neuropathy and fenofibrate treatment. To analyze the correlation of NF-κB、TNF-α、IL-6 and diabetic peripheral neuropathy.
Methods: Animal grouping and the samples acquirement were the same as part one. The expression at protein and mRNA level of NF-κB、TNF-α、IL-6 were measured by Western-blot method and PCR method respectively.
Results: 1、At the end of 32th week, compared with NC group, the expression of protein and mRNA level of NF-κB、TNF-α、IL-6 in sciatic nerve were higher in the DPN group rats(P<0.01); Compared with DPN group, after fenofibrate treatment ,the expression of protein and mRNA level of NF-κB、TNF-α、IL-6 in sciatic nerve were lower in DPNF group (P<0.05). 2、Correlation analyses suggested that the expression of protein and mRNA level of TNF-α、IL-6 have a positive correlation with NF-κB.And the expression of NF-κB has a positive correlation with serum FFA.
Conclusions: 1、The expression of protein and mRNA level of NF-κB、TNF-α、IL-6 in sciatic nerve in DPN group were higher and after fenofibrate treatment the expression of protein and mRNA level of NF-κB、TNF-α、IL-6 lower, and pathology damage of sciatic nerve improved.That indicated inflammation mybe one of the mechanisms of diabetic peripheral neuropathy.2、Correlation analyses suggested, the expression of protein and mRNA level of NF-κB、TNF-α、IL-6 in sciatic nerve associated with serum FFA,
引文
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