摘要
目的:探讨瞬时受体电位通道蛋白V1(TRPV1)和瞬时受体电位通道蛋白A1(TRPA1)在睾丸痛大鼠模型的表达及作用机制。方法:通过睾丸内注射2%醋酸的方法建立睾丸痛大鼠模型;造模后通过行为学实验检测大鼠自发痛计数与阴囊部热痛阈;RT-q PCR、Western印迹、免疫荧光检测T_(13)~L_1节段背根神经节(DRG)TRPV1和TRPA1的表达。结果:建模后大鼠自发痛计数较对照组明显增多[(22.63±3.42)次vs(0.13±0.35)次,P<0.01],热痛阈值下降,其下降峰值在注射后第4小时(4.85±1.00 s),与对照组(12.75±1.50 s)相比差异有统计学意义(P<0.01)。TRPV1和TRPA1均表达在DRG内神经元的胞膜上,与对照组相比,模型组大鼠DRG内TRPV1的mRNA水平上升至对照组的(1.77±0.34)倍,TRPA1的mRNA水平上升至对照组的(1.75±0.30)倍,且两种蛋白均表达上调,差异有统计学意义(P<0.05)。结论:TRPV1和TRPA1可能通过在DRG内表达上调,参与了睾丸痛大鼠模型的痛觉产生与外周痛敏的形成。
Objective: To explore the expressions of transient receptor potential vanilloid 1(TRPV1) and TRP ankyrin 1(TRPA1) in the dorsal root ganglion(DRG) and their action mechanisms in the rat model of orchialgia. Methods: The models of orchialgia were established in male SD rats by injection of 2% acetic acid into the testis. Then the number of spontaneous pain responses and withdrawal latency in the model rats were recorded by behavioral tests and the expressions of TRPV1 and TRPA1 in T13-L1 DRGs determined by RT-q PCR,Western blot and immunofluorescence staining. Results: Compared with the normal control rats,the orchialgia models showed a significant increase in the number of spontaneous pain responses(0. 13 ± 0. 35 vs 22. 63 ± 3. 42,P < 0. 01)and a decrease in the withdrawal latency at 4 hours after injection([12. 75 ± 1. 50] vs [4. 85 ± 1. 00] s,P < 0. 05). The mRNA expressions of both TRPV1 and TRPA1 were observed in the membrane of the neurons in the DRG,the former increased by 1. 77 times and the latter by 1. 75 times that of the control(P < 0. 05). Conclusion: The expressions of TRPV1 and TRPA1 were up-regulated in the DRG of the rat models of orchialgia,which may be involved in the allodynia and hyperalgesia of the rats.
引文
[1]Strebel RT,Leippold T,Luginbuehl T,et al.Chronic scrotal pain syndrome:Management among urologists in Switzerland.Eur Urol,2005,47(6):812-816.
[2]Caterina MJ,Leffler A,Malmberg AB,et al.Impaired nociception and pain sensation in mice lacking the capsaicin receptor.Science,2000,288(5464):306-313.
[3]Kelly S,Chapman RJ,Woodhams S,et al.Increased function of pronociceptive TRPV1 at the level of the joint in a rat model of osteoarthritis pain.Ann Rheum Dis,2015,74(1):252-259.
[4]Obata K,Katsura H,Mizushima T,et al.TRPA1 induced in sensory neurons contributes to cold hyperalgesia after inflammation and nerve injury.J Clin Invest,2005,115(9):2393-2401.
[5]黄宝星,曹万里,黄欣,等.大鼠慢性前列腺炎模型中TRPA1及相关炎症因子的表达.中华男科学杂志,2015,21(1):23-30.
[6]Yoshioka K,Tanahashi M,Uchida W.Behavioral and urological evaluation of a testicular pain model.Urology,2010,75(4):943-948.
[7]涂响安,余敬威.慢性睾丸痛的诊断与治疗.中华男科学杂志,2016,22(3):195-199.
[8]Parekattil SJ,Gudeloglu A,Brahmbhatt JV,et al.Trifecta nerve complex:Potential anatomical basis for microsurgical denervation of the spermatic cord for chronic orchialgia.J Urol,2013,190(1):265-270.
[9]Marconi M,Palma C,Troncoso P,et al.Microsurgical spermatic cord denervation as a treatment for chronic scrotal content pain:A multicenter open label trial.J Urol,2015,194(5):1323-1327.
[10]Woolf CJ,Salter MW.Neuronal plasticity:Increasing the gain in pain.Science,2000,288(5472):1765-1768.
[11]Bautista DM,Jordt SE,Nikai T,et al.TRPA1 mediates the inflammatory actions of environmental irritants and proalgesic agents.Cell,2006,124(6):1269-1282.
[12]Gopinath P,Wan E,Holdcroft A,et al.Increased capsaicin receptor TRPV1 in skin nerve fibres and related vanilloid receptors TRPV3 and TRPV4 in keratinocytes in human breast pain.BMC Womens Health,2005,5:2.
[13]Urano H,Ara T,Fujinami Y,et al.Aberrant TRPV1 expression in heat hyperalgesia associated with trigeminal neuropathic pain.Int J Med Sci,2012,9(8):690-697.
[14]Deberry JJ,Schwartz ES,Davis BM.TRPA1 mediates bladder hyperalgesia in a mouse model of cystitis.Pain,2014,155(7):1280-1287.
[15]Russell FA,Schuelert N,Veldhoen VE,et al.Activation of PAR(2)receptors sensitizes primary afferents and causes leukocyte rolling and adherence in the rat knee joint.Br J Pharmacol,2012,167(8):1665-1678.
[16]Bandell M,Story GM,Hwang SW,et al.Noxious cold ion channel TRPA1 is activated by pungent compounds and bradykinin.Neuron,2004,41(6):849-857.
[17]Fernandes ES,Russell FA,Spina D,et al.A distinct role for transient receptor potential ankyrin 1,in addition to transient receptor potential vanilloid 1,in tumor necrosis factor alpha-induced inflammatory hyperalgesia and Freund's complete adjuvantinduced monarthritis.Arthritis Rheum,2011,63(3):819-829.