结肠特异背根神经节神经元P_2X_3受体在大鼠内脏高敏感性中的作用  

Expression of P_2X_3 receptors in colon-specific dorsal root ganglion neurons in a rat model of colonic visceral hypersensitivity

作　　者：袁莉莉[1] 余跃[1] 蒋楠[1] 陈凤琴[1] 王巧民[1] 

机构地区：[1]安徽医科大学附属省立医院消化内科,安徽合肥230001

出　　处：《临床消化病杂志》2015年第6期343-346,共4页Chinese Journal of Clinical Gastroenterology

基　　金：安徽省自然科学基金(No:1208085 MH174);安徽省教育厅自然科学研究重点项目(No:KJ2010A192)

摘　　要：[目的]通过观察内脏高敏感模型大鼠结肠特异背根神经节(DRG)神经元P_2X_3受体表达和电生理特征,探讨P_2X_3受体在大鼠内脏高敏感性中的作用。[方法]10只幼鼠分为2组,经结直肠分别灌注乙酸诱导内脏高敏感模型(内脏高敏感组)、0.9%氯化钠溶液作对照(对照组);在结肠壁上注射1,1'-二(十八烷基)-3,3,3',3'-四甲基吲哚羰基花青高氯酸盐(DiI)逆行神经标记的DRG神经元为结肠特异DRG神经元,用免疫荧光技术观察其P_2X_3受体表达变化和膜片钳技术进行电生理记录。[结果]内脏高敏感组与对照组大鼠比较,结肠特异DRG神经元上P_2X_3受体免疫阳性率明显增加(45.47%∶32.15%,P<0.01)、结肠特异DRG神经元静息电位和阈电流降低(P<0.05)、动作电位频率增高(P<0.05)。AWR评分值与结肠特异DRG神经元上P_2X_3受体阳性率(r=0.86,P<0.01)、2倍阈电流刺激下动作电位频率(r=0.82,P<0.01)呈正相关,与阈电流值(r=-0.77,P<0.01)呈负相关。[结论]P_2X_3受体在结肠特异DRG神经元上表达上调且DRG神经元兴奋性增加与内脏高敏感的形成有密切关系。[Objective]To investigate the expression of P2X3receptors and electrophysiological characteristics of the colon-specific dorsal root ganglion（DRG）neurons in a rat model of colonic visceral hypersensitivity（CVH）. [Methods]CVH was induced by colorectal injection of acetic acid（AA）in newborn rats,Colon-specific DRG neurons were retrogradely labeled by injection of DiI（1, 1＇-Dioetadecyl-3,3,3＇, 3＇-Tetramethylindocarbocyanine perchlorate）into the colon wall. Expression of P2 X3 receptors were observed by immunofluorescenee and electrophysiological characteristics were measured by using patch clamp techniques. [Results]In AA rats, the expressing of P2X3 receptors was significantly higher in the colon-specific DRG neurons than controls. The average rheobase was significantly lower than controls. The frequency of APs in response to a 2 rheobase stimulation was significantly higher than controls. The AWR scores were positive correlated with the proportion expressing of P2X3 receptors（r=0.86 ,P〈0.01）and the frequency of APs（r = 0.82, P〈0.01）, but were negative correlated with rheobase（r= - 0.77, P〈0. 01）. [Conclusion]There is a close relationship between visceral hypersensitivity and increased expression of P2 X3 receptors and excitability in colon-specific DRG neurons.

关 键 词：内脏高敏感 背根神经节 膜片钳 P2X嘌呤能受体 

分 类 号：R574.62[医药卫生—消化系统]