肝脏缺血再灌注肝细胞凋亡与肝细胞糖原关系的实验研究

Relationship between hepatocellular glycogen content and hepatocellular apoptosis during liver ischemia-reperfusion

目的探讨肝脏缺血再灌注过程中增加肝细胞糖原含量能否抑制肝细胞凋亡的发生及其相关机制。方法成年新西兰大耳白兔21只,随机分为3组,于术前24h分别予以禁食(A组)、标准实验室饮食(B组)、标准实验室饮食加静脉注射葡萄糖(C组),检测3组肝脏缺血再灌注过程中肝细胞凋亡情况及肝细胞内游离Ca2+浓度、肝细胞膜Ca2+-ATP酶活性变化。结果 3组肝脏于再灌注1h时,组织内可见明显的肝实质细胞凋亡现象,其凋亡细胞数各组间均存在显著性差异(P<0.01)。此外,3组肝脏缺血前肝细胞内游离Ca2+浓度及肝细胞膜Ca2+-ATP酶活性均无显著性差异(P>0.05),但于缺血45min及再灌注1h时差异则具有显著性(P<0.05或P<0.01)。结论增加肝细胞内糖原含量可显著拮抗肝脏缺血再灌注过程中肝细胞凋亡,其可能的原因在于糖原含量高的肝实质细胞内ATP充裕,肝细胞膜Ca2+-ATP酶功能完善,细胞内外Ca2+平衡相对稳定。

Objective To investigate whether an increase in hepatocellular glycogen content could inhibit hepatocellular apoptosis during liver ischemia-reperfusion,and to explore its related mechanism.Methods 21 New Zealand white rabbits were randomly divided into three groups.They were given fasting diet(group A),standard laboratory diet(group B),and standard laboratory diet plus intravenous injection of glucose(group C).The hepatocellular apoptosis,concentration of intra-hepatocellular free Ca2+ and activity changes of membrane Ca2+-ATPase were detected during ischemia-reperfusion in the three groups.Results Obvious hepatocellular apoptosis were found after reperfusion for 1 h,and the numbers of apoptotic cells had significance differences among the three groups(P<0.01).In addition,there were no significant differences in the concentration of intra-hepatocellular free Ca2+ and the activity of membrane Ca2+-ATPase among the three groups before ischemia,but after ischemia for 45 min and reperfusion for 1 h,the differences had statistical significance(P<0.05 or P<0.01).Conclusion Increasing hepatocellular glycogen content may remarkably antagonize hepatocellular apoptosis during liver ischemia-reperfusion,possibly due to the abundant ATP,good function of membrane Ca2+-ATPase and relative stabilization of extra and intracellular Ca2+ in hepatocytes with high glycogen.