Farghali H, Kmonícková E, Lotková H, Martínek J
Institute of Pharmacology, First Faculty of Medicine, Charles University, Prague, Czech Republic.
Physiol Res. 2000;49(2):261-8.
The aim of this study was to investigate the effects of calcium channel blockers on tertbutyl hydroperoxide (TBH) induced liver injury using isolated perfused rat hepatocytes. Rat hepatocytes were immobilized in agarose threads and perfused with Williams E medium. Hepatocyte injury was induced by the addition of tertbutyl hydroperoxide (1 mM) to the perfusion medium 30 min after the addition of either verapamil or diltiazim. Hepatocyte injury was observed by monitoring the functional and metabolic competence of hepatocytes or by ultrastructural morphological examination of hepatocytes. Verapamil (0.5 mM) reduced lactate dehydrogenase leakage in TBH-injured hepatocytes as compared to the controls (154+/-11% vs. 247+/-30%). Lipid peroxides production was reduced after verapamil pretreatment as compared to the controls and oxygen consumption was increased by pretreatment of hepatocytes with verapamil. Verapamil pretreatment increased the protein synthesis activity at both levels of granular endoplasmic reticulum and free polysomes in cytoplasm and decreased ATPase activity. Diltiazem was qualitatively effective as verapamil. It is concluded that in hepatocyte oxidative injury, calcium channel blockers exhibited hepatoprotective properties. The hepatoprotective effect of calcium channel blockers was accompanied by a decrease in ATPase activity, which may implicate a normalization of Ca2+i after TBH intoxication.
本研究旨在利用离体灌注大鼠肝细胞，探讨钙通道阻滞剂对叔丁基过氧化氢（TBH）诱导的肝损伤的影响。将大鼠肝细胞固定在琼脂糖纤维中，并用Williams E培养基进行灌注。在加入维拉帕米或地尔硫䓬30分钟后，向灌注培养基中加入叔丁基过氧化氢（1 mM）以诱导肝细胞损伤。通过监测肝细胞的功能和代谢能力或对肝细胞进行超微结构形态学检查来观察肝细胞损伤。与对照组相比，维拉帕米（0.5 mM）可降低TBH损伤肝细胞中乳酸脱氢酶的泄漏（分别为154±11%和247±30%）。与对照组相比，维拉帕米预处理后脂质过氧化物的产生减少，且维拉帕米预处理可增加肝细胞的耗氧量。维拉帕米预处理可提高细胞质中粗面内质网和游离多核糖体水平的蛋白质合成活性，并降低ATP酶活性。地尔硫䓬的作用与维拉帕米定性相同。结论是，在肝细胞氧化损伤中，钙通道阻滞剂具有肝脏保护特性。钙通道阻滞剂的肝脏保护作用伴随着ATP酶活性的降低，这可能意味着TBH中毒后细胞内钙离子浓度恢复正常。
