Objective: To observe the effect of electroacupuncture (EA) of "Tianshu"(ST25) and "Shangjuxu"(ST37)on gastrointestinal motility, psychological abnormality and expression of RhoA and ROCK protein in rats with diarrhea predominant irritable bowel syndrome (IBS-D), so as to explore its underlying mechanism in improving IBS-D.
Methods: Thirty-six male rats were randomly and equally divided into control, model, EA and medication groups (n=9 in each group). The IBS-D model with psychological abnormality was established by gavage of dinitrobenzene sulfonic acid (DNBS) + chronic restraint stress. EA (2 Hz/100 Hz, 0.3 mA) was applied to bilateral ST25 and ST37 for 20 min, once a day for 7 days. Rats of the medication group received gavage of pinaverium bromide solution (15 mg/kg), once a day for 7 days. The rats' food intake in 24 h, body mass and colonic contraction waves were recorded. The anhedonia-related behavior was measured using the sucrose consumption test. The elevated plus maze test (the open-arm residence time ratio) was used to assess the anxiety-like behavior. The small intestinal propulsion rate test was used to assess the intestinal motility. The expression levels of RhoA and ROCK proteins in the colonic tissue were measured by Western blot.
Results: After modeling, the body mass, food consumption, sucrose preference index, the open-arm residence time ratio andlatency of colonic contraction waves were significantly decreased (P<0.05), and the number of contraction waves, intestinal propulsive rate, and the expression levels of RhoA and ROCK proteins considerably increased (P<0.01，P<0.05) in the model group relevant to the control group. Following the interventions, the decrease of body mass, food consumption, sucrose preference index, open-arm residence time ratio and latency of contraction waves, and the increase of the contraction waves, intestinal propulsive rate, and the expression levels of RhoA and ROCK proteins were all reversed by both EA and medication (P<0.05，P<0.01). The effect of EA was significantly superior to that of medication in increasing the sucrose pre-ference index (P<0.05).
Conclusion: EA can improve both colonic motility and psychological disorders in IBS-D rats with psychological disorder, which may be related to its function in down-regulating the expression of colonic RhoA and ROCK proteins.
目的：观察电针“天枢”“上巨虚”对腹泻型肠易激综合征(IBS-D)大鼠胃肠道动力障碍、心理异常及结肠组织Ras同源基因家族蛋白A(RhoA)、Rho相关激酶(ROCK)蛋白表达的影响，探讨电针治疗IBS-D的作用机制。方法：SD大鼠随机分为对照组、模型组、电针组、药物组，每组9只。通过二硝基苯磺酸灌胃+慢性束缚应激法建立伴有心理异常的IBS-D大鼠模型。电针组予电针双侧“天枢”“上巨虚”，每次20 min，1次/d，持续7 d。药物组将匹维溴铵按体质量15 mg/kg研磨成粉，与1 mL 0.9%氯化钠溶液混合均匀后，灌胃给药，1次/d，持续7 d。观察各组大鼠一般状态，测定其体质量及摄食量，进行内脏敏感性检测、糖水偏嗜实验及高架十字迷宫测试，以墨汁灌胃法检测小肠推进率，Western blot法检测结肠组织中RhoA、ROCK蛋白的表达。结果：与对照组比较，模型组大鼠一般状态较差，体质量、摄食量、糖水偏好指数及开臂停留时间百分比均降低(P<0.05)，结肠收缩波个数明显增加(P<0.01)，收缩波潜伏期明显缩短(P<0.05)，小肠推进率及结肠组织中RhoA、ROCK蛋白表达水平均升高(P<0.05)。与模型组比较，电针组、药物组大鼠一般情况有所改善，体质量、摄食量、糖水偏好指数及开放臂停留时间百分比均升高(P<0.05)，收缩波个数减少(P<0.05)，收缩波潜伏期延长(P<0.05)，小肠推进率及结肠组织中RhoA、ROCK蛋白表达水平均降低(P<0.01，P<0.05)。与药物组比较，电针组糖水偏好指数升高(P<0.05)。结论：电针可以同时改善IBS-D大鼠结肠动力障碍及心理异常，其作用机制可能与降低结肠组织RhoA、ROCK蛋白表达水平有关。.
Keywords: Diarrheal predominant irritable bowel syndrome; Electroacupuncture; Gastrointestinal motility; ROCK; RhoA.