GENERATION OF HYDROPEROXIDES IN ISOLATED RAT HEPATOCYTES AND HEPATIC MITOCHONDRIA EXPOSED TO HYDROPHOBIC BILE-ACIDS
GENERATION OF HYDROPEROXIDES IN ISOLATED RAT HEPATOCYTES AND HEPATIC MITOCHONDRIA EXPOSED TO HYDROPHOBIC BILE-ACIDS
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DOI：
10.1016/0016-5085(95)90585-5
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发表时间：
1995-10-01
期刊：
影响因子：
29.4
通讯作者：
MCKIM, JM
中科院分区：
文献类型：
--
作者：
SOKOL, RJ;WINKLHOFERROOB, BM;MCKIM, JM
背景与目的：胆汁淤积性疾病引起肝损伤的机制尚不清楚。在胆汁淤积过程中，疏水性胆汁酸在肝细胞中的积累会导致氧自由基的产生和氧化损伤，这一假说得到了检验。本研究的目的是确定疏水性胆汁酸毒性是否与分离的大鼠肝细胞和线粒体过氧化氢生成增加有关。方法：用牛磺鹅去氧胆酸(TCDC；0~2000mU/L)或牛磺胆酸(TC，1000mU/L)染毒肝细胞，测定细胞损伤、细胞内过氧化氢生成和硫代巴比妥酸反应物质(TIP)。将分离的线粒体分别与400mU/L鹅去氧胆酸或400mU/L胆酸孵育，用荧光法测定过氧化氢的产生。结果：TCDC暴露4小时后，肝细胞损伤、过氧化氢生成和泪液增多，而TC无明显变化。过氧化氢的产生先于肝细胞损伤和泪液堆积。肝细胞与抗氧化剂d-α-生育酚琥珀酸酯预先孵育，完全消除了细胞损伤、过氧化氢和泪水的产生。暴露于鹅去氧胆酸的线粒体过氧化氢生成增加。结论：在疏水性胆汁酸诱导的肝细胞毒性中，线粒体产生的细胞内过氧化氢似乎是早期事件。抗氧化剂可能对胆汁淤积症有好处。
Background & Aims: The mechanisms causing liver injury in cholestatic diseases are unclear. The hypothesis that accumulation of hydrophobic bile acids in hepatocytes during cholestasis leads to generation of oxygen free radicals and oxidative injury was tested. The aim of this study was to determine if hydrophobic bile acid toxicity is associated with increased hydroperoxide generation in isolated rat hepatocytes and mitochondria. Methods: Hepatocytes were exposed to taurochenodeoxycholic acid (TCDC; 0-2000 mu mol/L) or taurocholic acid (TC; 1000 mu mol/L), and cellular injury, intracellular hydroperoxide generation, and thiobarbituric acid-reacting substances (TEARS) were measured. Isolated mitochondria were incubated with 400 mu mol/L chenodeoxycholic acid or 400 mu mol/L cholic acid, and hydroperoxide generation was measured fluorometrically. Results: Hepatocyte injury, hydroperoxide generation, and TEARS increased over 4 hours on exposure to TCDC but not TC. Hydroperoxide generation preceded hepatocyte injury and accumulation of TEARS. Preincubation of hepatocytes with the antioxidant, d-alpha-tocopheryl succinate, completely abrogated cellular injury, hydroperoxide, and TEARS generation. Hydroperoxide generation was increased in mitochondria exposed to chenodeoxycholic acid. Conclusions: Intracellular generation of hydroperoxides by mitochondria appears to be an early event in hydrophobic bile acid-induced hepatocyte toxicity. Antioxidants may be of benefit in cholestasis.