三七总皂甙对大鼠肝脏低温保存再灌注期间肝细胞凋亡的影响

目的　研究三七总皂甙 (PNGS)对大鼠肝脏低温保存再灌注期间肝细胞凋亡的影响及其机制。方法　采用大鼠离体肝脏再灌注模型 (IPRL) ,用Fura 2法测定低温保存 2h后肝细胞内钙离子浓度 ;经乳酸林格氏液 (LR)低温保存 2 4h的肝脏再灌注 30min后进行肝脏功能检测、氧自由基代谢产物、肝细胞凋亡、Bcl 2蛋白表达及形态学观察。LR和DMEM液中加入不同浓度PNGS。结果　大鼠肝细胞内钙离子浓度、MDA、SOD、肝细胞凋亡及Bcl 2蛋白表达阳性率等项指标各实验组明显好于对照组 (P <0 0 1) ,PNGS对大鼠肝细胞凋亡的保护作用显示出剂量依赖性 ,在 2 0 0～ 6 0 0mg范围内随剂量增加保护作用随之增强 (P <0 0 1) ,在 80 0～ 10 0 0mg范围内虽有增强 ,但无明显差别 (P >0 0 5 )。结论　PNGS减轻了大鼠肝脏在低温保存再灌注期间肝细胞凋亡 ,可能与通过抑制钙超载、抗氧自由基损伤、提高Bcl 2蛋白表达作用有关。

Effects of Panax notoginseng saponins on hepatocellular apoptosis during cold preservation-reperfusion of rat liver

Objective To investigate the effects of Panax notoginseng saponins (PNGS) on hepatocellular apoptosis during cold preservation-reperfusion of rat liver. Methods The model of isolated perfusion of liver was established in rats. Fura-2 method was used to determine the intracellular calcium 2 h after cold preservation of the liver samples. After the liver samples were subjected to hypothermal preservation using Lactate Ringer's (LR) solution containing different concentrations of PNGS for 24 h and reperfused for 30 min, the liver function, free radical content, hepatocellular apoptosis, Bcl-2 protein expression and morphological changes were determined. Results The intracellular calcium content, MDA, SOD, hepatocellular apoptosis and positivity of Bcl-2 protein expression were better in the experimental group than in the control (P<0.01). At the dose of 200-600 mg, PNGS could effectively protect liver cells from apoptosis and its effects were dose-dependent. Conclusions PNGS can relieve hepatocellular apoptosis during cold preservation of the liver samples. The mechanism might be inhibiting calcium overload and hepatic injury by free radicals and enhancing the expression of Bcl-2 protein.