Ohtani K, Miyabara K, Okamoto E, Kamei M, Matsui-Yuasa I
Faculty of Human Life Science, Osaka City University, Japan.
Biosci Biotechnol Biochem. 1996 Dec;60(12):1989-93. doi: 10.1271/bbb.60.1989.
The effects of 7-ketocholesterol on rat hepatocytes prepared by collagenase perfusion were examined. The viability of cells incubated with 100 microM 7-ketocholesterol was significantly lower than those with cholesterol, although the LDH activity in the cultured medium remained unchanged during the incubation. Hepatocytes treated with 7-ketocholesterol produced large amounts of .NO and O2- in the early stage of incubation. Treatment of the hepatocytes with Carboxy-PTIO, which selectively scavenged .NO, or with L-NMMA, an inhibitor of .NO synthase, increased the cell viability. The addition of 7-ketocholesterol to the culture medium tended to increase the ratio of total sterol to phospholipid of the hepatocytes in a time-dependent manner without changing the content of phospholipid. No lipid peroxidation or oxidation of the cellular SH groups, protein SH and glutathione, was apparent. Vitamin E added 1 h before the addition of 7-ketocholesterol prevented the hepatocytes from cell death by suppressing the incorporation of 7-ketocholesterol into the hepatocytes and by scavenging O2-.
研究了7-酮胆固醇对胶原酶灌注法制备的大鼠肝细胞的影响。用100微摩尔/升7-酮胆固醇孵育的细胞活力显著低于用胆固醇孵育的细胞，尽管孵育期间培养基中的乳酸脱氢酶活性保持不变。用7-酮胆固醇处理的肝细胞在孵育早期产生大量的一氧化氮（·NO）和超氧阴离子（O₂⁻）。用选择性清除·NO的羧基-PTIO或一氧化氮合酶抑制剂L-NMMA处理肝细胞，可提高细胞活力。向培养基中添加7-酮胆固醇倾向于以时间依赖性方式增加肝细胞中总甾醇与磷脂的比例，而不改变磷脂含量。未观察到脂质过氧化或细胞内巯基、蛋白质巯基和谷胱甘肽的氧化现象。在添加7-酮胆固醇前1小时添加维生素E，通过抑制7-酮胆固醇进入肝细胞和清除O₂⁻，防止肝细胞死亡。
