谷氨酰胺对急性肝损伤大鼠肠黏膜屏障的作用

目的 探讨谷氨酰胺(glutamine,GLN)对急性肝损伤大鼠肠黏膜屏障的作用.方法 61只清洁级Wistar大鼠随机分为3组:对照组、模型组、GLN干预组.采用脂多糖(lipopolysaccharide,LPS)和D-半乳糖胺(D-galactosamine,D-Gal)腹腔注射法建立急性肝损伤大鼠模型.检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)和总胆红素(TBiL)水平;光镜下及电镜下观察大鼠肝脏及肠道病理学改变;末端脱氧核苷酸转移酶(TdT)介导的缺口末端标记技术(TUNEL)检测细胞凋亡;高压液相离子色谱仪(HPLC-PED)检测大鼠肠黏膜通透性的改变.结果 模型组及GLN干预组大鼠死亡率差异无统计学意义(P>0.05);模型组及GLN干预组大鼠血清ALT、AST和TBIL水平差异无统计学意义(P>0.05);三组肠黏膜通透性差异无统计学意义(P>0.05);光镜下GLN干预组与模型组大鼠肝脏损伤程度差异无统计学意义;肠道未见明显病变;透射电镜下模型组和GLN干预组大鼠肝脏和肠道出现线粒体和细胞核等损伤,GLN干预组较模型组大鼠损伤轻;GLN干预组肝脏和肠道的凋亡指数(Apoptosis index,AI)显著低于模型组(P<0.05).结论 脂多糖可以造成D-半乳糖胺致敏大鼠急性肝损伤模型,造模前给予谷胺酰胺干预可能对于改善肝功能,保护肠黏膜的通透性,降低死亡率没有显著性作用.

Effect of glutamine on intestinal mucosal barrier function in rats with acute hepatic injury

Objective To explore the role of glutamine in LPS and D-Gal induced acute hepatic injury. Methods A total of 61 Wistar rats were randomly divided into three groups:control group, model group and GLN pretreated group.The animal model was established by LPS and D-Gal intraperitoneal injection. GLN at dose of 1 g/kg was intragastrically administrated for 7 d before intraperitoneal injection. To evaluate the hepatic injury, the serum alanine aminotransferase(ALT), aspartate aminotransferase(AST) and total bilimbin(TBiL) were detected by automatic biochemistry analysator. The liver and bowel tissue was observed by lightmicroscope and transmission electron microscope(TEM). The apoptosis of hepatocyte was detected by TUNEL. HPLC-PED was used in the study of intestinal permeability. Result No significant differences were noted between ALT, AST, TBIL level, death rate and intestinal permeability(L/M) between model group and GLN pretreated group;In microscope, the confused structure of hepatic injury and inflammatory infiltration were similar between model group and GLN pretreated greup.The injury of bowel was not obviously. Compared with the model group, there was better trend in liver and bowel in GLN pretreated group by transmission electron microscope(TEM) .The apoptosis index in GLN pretreated group were lower than those in model group. Conclusion LPS can induce acute liver injury in D-Gal-sensitized rats. Glutamine has't the trend of protecting liver function and intestinal barrier function, decreasing death rates.