电刺激迷走神经对大鼠重症急性胰腺炎血浆内皮素和一氧化氮水平的影响及意义

摘要

目的 观察电刺激迷走神经对大鼠重症急性胰腺炎(SAP)血浆内皮素、一氧化氮的影响.方法 将SD大鼠80只随机分为假手术(Sham)组8只、SAP组24只、迷走神经切断(VNC)组24只和迷走神经刺激(VNS)组24只.其中SAP组、VNC组和VNS组根据1、3、6小时不同取材时间各自分3小组,每组8只.经胆胰管逆行注入5％牛磺胆酸钠建立大鼠SAP组模型；SAP组制模后,立即切断双颈部迷走神经建立VNC组模型；VNC组造模后,立即予以左迷走神经近心端以5V,2 ms和1Hz强度的电流持续刺激20 min产生VNS组模型.l、3、6h剖杀各组大鼠.检测各组大鼠血浆中ET和NO水平,观察胰腺病理改变.结果:SAP组和VNC组ET、NO、ET/NO比值和胰腺病理组织学评分较Sham组均显著增高(P＜0.05).相比SAP组,VNC组NO含量降低,ET/NO比值及胰腺病理组织学评分显著上升(P＜0.05).VNS组ET/NO和胰腺病理组织学评分显著下降,NO含量明显升高,较SAP组和VNC组(P＜0.05).结论 迷走神经刺激可增加一氧化氮合成或释放,减轻ET/NO比值失衡,改善微循环,减轻大鼠重症胰腺炎胰腺病理损害.%Objective To investigate the effects of electrical stimulation of vagus nerve on plasma levels of nitric oxide( NO) and endothelin (ET) in severe acute pancreatitis in rats. Methods Eighty adult male Sprague-Dawley rats were randomized into 4 groups: shame-operation group (n=8) , severe acute pancreatitis group (n =24) , vagus nerve cut group (n =24) and vagus nerve stimulation group ( n = 24) . And severe acute pancreatitis group, vagus nerve cut group and vagus nerve stimulation group respectively divivded into lh,3h and 6h group(n =8). The SAP models of rats was induced by retrograde injection of 5% sodium taurocholate into biliopancreatic duct in rats. The VNC models of rats were established by bilateral cervical vagotomy after SAP induction. The VNS models of rats was made by constant electric stimulation(5V,2ms,1HZ) to the left cervical vagus nerve trunk proximal part for 20 min after VNC induction. Groups of rats were sacrificed atlh,3h,6h. Endothelin and nitric oxide leavels were measured in blood of each group rats and histological changes of the pancreas were observed. Results Compared with rats in Sham group, ET and NO levels,the value of ET/NO and pancreatic histopathological score were significantly higher in rats of the SAP group and VNC group ( P < 0. 05 ). In VNC group, NO level was not increased obviously, the value of ET/NO and pancreatic histopathological score upgraded dramatically compared to SAP group (P <0. 05). In VNS group, the value of ET/NO and pancreatic histopathological score were obviously depressed, and NO level was significantly arised compared to SAP group and VNC group (P <0. 05). Conclusion Electrical stimulation of vagus nerves can relief injury degree of severe acute pancreatitis in rats by increaseing NO produce and release and lessening the disequilibrium of N0/ET ratio to improve microcirculation disorder.