目的:从线粒体介导的内源性途径分析大鼠肝再生早期肝细胞凋亡执行酶caspase-3激活的机制。方法:雄性SD大鼠35只,分成模型组15只(70%肝切除制作肝再生模型)、假手术组15只和正常对照组5只。模型组和假手术组根据时间分为术后3、6和24 h三个亚组,每个亚组5只。取各组大鼠肝组织,制备肝匀浆液。荧光法测肝组织凋亡酶caspase-3和caspase-9的活性;酶联免疫分析法测谷胱甘肽过氧化酶(GSH-Px)活性;硝酸还原法测NO含量。结果:与假手术组相比,模型组凋亡酶caspase-3和caspase-9的活性在肝再生早期(术后3、6 h组)显著增高(P〈0.01);GSH-Px水平显著降低,NO分泌量显著增高(P〈0.01)。结论:肝再生早期,肝组织处于氧化应激状态,线粒体介导的内源性途径参与凋亡执行酶的激活。
Objective: To analyze the activation mechanism of hepatic apoptosis-related enzyme caspase-3 during the early phase of liver regeneration in rats from the perspective of mitochondria-mediated endogenous signal pathway. Methods: Thirtyfive male SD rats were randomly divided into 3 groups: model group [70% partial hepatectomy (PH), n= 15], sham-operated group (n= 15), and control group (n = 5). The former 2 groups were further divided into 3 subgroups according to time after operation (3 h,6 h,and 24 h after operation,5 animals in each group). The animals in all groups were sacrificed and the liver homogenates were prepared. Using the fluorescence method, we determined the activities of hepatic caspase-3 and caspase-9 at 3 different time points after operation. The activity of glutathione peroxidase (GSH-Px) and the content of NO were examined by enzyme immunoassay and nitrate reductase assay,respectively. Results: The activities of hepatic caspase-3 and 9 both increased significantly compared with those of sham-operated group (P〈0.01) at 3 h and 6 h after operation; the level of GSH-Px was significantly decreased and the content of NO was significantly increased compared with those of the sham-operated group (P〈 0.01). Conclusion: Hepatic tissue is under oxidative stress during the early phase of liver regeneration,and the mitochondria-mediated endogenous signal pathway is involved in the activation of caspase-3.