大鼠肝再生时线粒体通透性转换的变化

目的:研究大鼠肝再生过程中肝细胞线粒体膜通透性转换(PT)的变化规律.方法:SD大鼠肝70%部分切除(PH)制作肝再生模型,断头取肝分离线粒体后,通过检测静息态和不同浓度钙离子诱导下线粒体悬液在540 nm处光密度值(D540)变化来观察线粒体PT的时相变化.结果:与对照组比较,大鼠肝再生早期(PH后0～24 h)和后期(PH后120～168 h)都表现为肝线粒体先收缩后肿胀,也即通透性先下降后增高;同时大鼠肝再生早期肝线粒体可明显抵抗钙离子的诱导作用,而PH后24 h和168 h组的大鼠肝线粒体对钙离子的诱导非常敏感.环孢素A(CsA)可阻断钙的诱导作用.结论:大鼠肝再生过程中线粒体PT出现明显规律性改变,这可能与肝再生过程中线粒体氧化磷酸化的变化以及肝再生的启动和终止有关.

Changes of mitochondrial permeability transition during rat liver regeneration

Objective:To study the changes of mitochondrial permeability transition (PT) during rat liver regeneration. Methods: Liver regeneration model was produced by 70% partial hepatectomy (PH) in male SD rats. The rats were killed by decapitation and the livers were removed, weighed and processed for isolation of mitochondria. Determinations of the mitochondrial permeability transition, with or without different concentrations of Ca 2+ induction, were based on the absorbance changes of the mitochondrial suspension at 540 nm. Results: The mitochondria was first shrunk and then swollen during early phase (0 24 h after PH) and late phase (120 168 h after PH) of rat liver regeneration.The permeability of mitochondria first decreased and then increased. Meanwhile, the mitochondria isolated from rat liver on 3 h, 6 h after PH were more resistant to Ca 2+ induced permeabilization than other liver regeneration groups and sham operated groups, while the mitochondria isolated from rat liver on 24 h, 168 h after PH were more sensitive to Ca 2+ induced permeabilization than other groups. Cyclosporin A (CsA) prevented the changes in mitochondrial membrane permeability.Conclusion:Remarkable changes of mitochondrial permeability transition during rat liver regeneration may be the basis of the alterations of oxidative phosphorylation, and it may also be related to the initiation and the end of liver regeneration after partial hepatectomy.