N-乙酰-L-色氨酸对大鼠肝脏缺血再灌注后肠损伤的保护作用

目的 探讨N-乙酰-L-色氨酸(L-NAT)对大鼠肝脏缺血再灌注中肠损伤的保护作用.方法 将健康成年雄性SD大鼠24只分为假手术组(Sham组)、缺血再灌注组(IR组)和缺血再灌注加L-NAT组(IR+ L-NAT组).用夹闭肝中叶和左叶肝蒂分支的方法制作肝缺血再灌注模型,用苏木素-伊红(HE)染色法观察小肠组织的形态学结构,用免疫组织化学染色观察激活型Caspase-3、Bax、Bcl-2的表达.结果 (1)IR组小肠绒毛结构破坏,肠黏膜充血脱落,上皮细胞变性坏死,出现炎症细胞浸润;L-NAT可使之减轻.(2)免疫组织化学染色显示,与Sham组相比,IR组激活型Caspase-3、Bcl-2和bax的表达升高,L-NAT干预后,Caspase-3和Bax的表达下降,而Bcl-2的表达进一步升高.结论 L-NAT可抑制肝脏缺血再灌注损伤引起的小肠上皮细胞凋亡,减轻小肠上皮细胞损伤.

Protective effect of N-acetyl-L-tryptophan on intestinal damage after rat hepatic ischemia reperfusion

Objective To investigate the protective effects of N-acetyl-L-tryptophan (L-NAT) on intestinal damage after rat hepatic ischemia reperfusion.Methods Twenty-four healthy adult rats were divided into the sham operation group (Sham),ischemia reperfusion group (IR),ischemia reperfusion and N-acetyl-L-tryptophan group(IR+L-NAT).The hepatic ischemia reperfusion model was established by occluding the afferent vessels of the left and middle lobes.The morphological structures of the small intestine were observed by hematoxylin-eosin (HE) staining.The expressions of active caspase-3,Bax and Bcl-2 were detected by immunohistochemistry staining.Results (1) In the IR group,the structure of intestinal villis was destroyed,the intestinal mucosa showed congestion and exfoliation,the epithelial cells had degeneration and necrosis,and infiltration of inflammatory cells appeared;which could be alleviated by L-NAT.(2)The immunohistochemistry showed that compared with the Sham group,the expression of active caspase-3,Bcl-2 and Bax in the IR group was increased,after L-NAT intervention,the Bax and caspase-3 expression was decreased,while the Bcl-2 expression was further increased.Conclusion L-NAT could inhibit the apoptosis of small intestinal epithelial cells caused by liver ischemic reperfusion and attenuates intestinal epithelial damage.