前列腺素E1预处理对胆汁淤积大鼠肝缺血再灌注损伤的保护作用

摘要

目的 探讨前列腺素E1(PGE1)对胆汁淤积肝脏缺血再灌注损伤的保护机制.方法 36只雄性Wistar大鼠随机分为前列腺素E1组(PGE组)和生理盐水组(NS组).PGE组肝缺血前15 min至再灌注60 min经门静脉持续泵入PGE1(0.5 μg·kg-1·min-1),NS组给予等量生理盐水.结扎胆总管,建立胆汁淤积模型.7d后PrinCe法阻断入肝血流15 min,于再灌注1、6和24h,检测血清生化酶和胆红素,以及肝组织髓过氧化物酶(MPO)、TNFα、Bcl-2、Bax、热休克蛋白(HSP)70和病理组织学改变.结果 再灌注1、6和24 h,2组TBil和DBil水平比较,差异均无统计学意义(P值均＞0.05).再灌注1、6和24 h,PGE组ALT、AST、MPO和TNFα水平均显著低于NS组,差异均有统计学意义(P值均＜0.05).再灌注1、6和24 h,PGE组Bcl-2水平显著高于NS组,Bax水平显著低于NS组,差异均有统计学意义(P值均＜0.05).再灌注1h和6h,PGE组HSP70 mRNA表达水平明显高于NS组,差异均有统计学意义(P值均＜0.05).再灌注24 h,2组HSP70 mRNA表达水平差异无统计学意义(P＞0.05).PGE组肝组织损伤程度均较NS组轻,表现为肝细胞肿胀减轻,肝细胞坏死减少,肝细胞索及肝窦结构比较清晰,肝细胞索排列较规则,肝窦明显增宽.结论 PGE1通过减少中性粒细胞浸润和Bax表达,以及增强HSP70和Bcl-2表达保护胆汁淤积肝脏的缺血再灌注损伤.%Objective To investigate the protective mechanism of prostaglandin E1 (PGE1) against liver ischemia-reperfusion injury in rats with cholestasis.Methods A total of 36 male Wistar rats were randomly divided into PGE1 group (PGE group) and normal saline group (NS group).The rats in the PGE group were treated with continuous pump of PGE1 (0.5 μg/kg/min) from 15 minutes before liver ischemia to 60 minutes of reperfusion,and those in the NS group were given normal saline of the same volume.Common bile duct ligation was performed to establish a rat model of cholestasis.Seven days later,Pringle maneuver was used to perform hepatic inflow occlusion for 15 minutes,and serum levels of enzymes and bilirubin were measured at 1,6,and 24 hours of reperfusion,as well as the levels of myeloperoxidase (MPO),tumor necrosis factor α (TNFα),Bcl-2,Bax,and human heat shock protein 70 (HSP70) and histopathological changes.Results At 1,6,and 24 hours of reperfusion,there were no significant differences in total bilirubin and direct bilirubin between the two groups (both P ＞ 0.05),and the PGE group had significantly lower levels of alanine aminotransferase,aspartate aminotransferase,MPO,and TNFα than the NS group (all P ＜ 0.05).At 1,6,and 24 hours of reperfusion,compared with the NS group,the PGE group had a significantly higher level of Bcl-2 and a significantly lower level of Bax (both P ＜ 0.05).At 1 and 6 hours of reperfusion,the PGE group had significantly higher mRNA expression of HSP70 than the NS group (P ＜0.05),and at 24 hours of reperfusion,there was no significant difference in mRNA expression of HSP70 between the two groups (P ＞ 0.05).Compared with the NS group,the PGE group had a lower degree of liver injury,which manifested as reduced hepatocyte swelling and necrosis,clear structures of the hepatic cords and the hepatic sinusoids,regular arrangement of hepatic cords,and widened hepatic sinusoids.Conclusion PGE1 protects the liver with cholestasis against ischemia-reperfusion injury by reducing neutrophil infiltration and Bax expression and upregulating the expression of HSP70 and Bcl-2.