牛磺酸对大鼠肝缺血再灌注后小肠损伤的保护作用

Protective effect of taurine on small intestinal injury induced by hepatic ischemia/reperfusion in rats

目的探讨牛磺酸对大鼠肝缺血再灌注(I/R)后小肠损伤的保护作用。方法将大鼠随机分成假手术组,肝I/R组,牛磺酸预处理+肝I/R组;采用阻断肝动脉、门静脉30min后再灌注的方法,制作肝I/R模型。各组于再灌注3,6,24h分别采血,测定二胺氧化酶(DAO)数值,检测小肠功能;同步切取小肠,测定肠道组织中的SOD及MDA含量,评价肠道自由基损伤程度;切片后行苏木素-伊红(HE)染色,观察病理形态学改变;原位末端标记法(TUNEL)测定细胞凋亡;免疫组化法测定caspase-3表达。结果与假手术组比较,肝I/R组SOD水平明显降低(P<0.05),MDA和DAO水平明显升高(P<0.05),小肠病理损伤严重,凋亡指数明显升高(P<0.05),caspase-3阳性率明显增加(P<0.05)。与I/R组同时间点比较,牛磺酸预处理+I/R组各项指标均明显改善(均P<0.05)。结论牛磺酸对肝I/R后小肠损伤具有保护作用。

Objective To investigate the protective effect of taurine on small intestinal injury induced by liver ischemia/reperfusion in rats. Methods Rats were randomly assigned into sham operation control group,hepatic I/R group and taurine pretreatment plus hepatic I/R group.Hepatic I/R model was produced by occlusion of both hepatic artery and portal vein for 30 min and then followed by reperfusion.The blood samples were collected at 3,6 and 24 h after reperfusion in each group,and the serum levels of diamine oxidase（DAO） were determined to evaluate the function of small bowels.Meawhile,the rats′small bowels were excised to measure the contents of SOD and MDA in intestinal tissues,for evaluating the degree of free radical injury.Tissues of small bowels were sectioned and the histopathological changes were observed with HE staining,TUNEL method was used to examine the apoptosis,and caspase-3 expression was detected by immunohistochemistry. Results Compared with control group,the serum level of SOD in hepatic I/R group was significantly decreased（P〈0.05）,while the serum level of MDA and DAO significantly increased（P〈0.05）.The small bowel of hepatic I/R group showed severe injury,and its apoptotic index as well as the caspase-3 expression were significantly increased compared with control group（both P〈0.05）.All indices examined at each predefined time point of the taurine pretreated group were significantly improved compared with those of the hepatic I/R group（all P〈0.05）. Conclusions Taurine has protective effects on small intestinal injury induced by hepatic ischemia/reperfusion.