Razzouk C, McManus M E, Hayashi S, Thorgeirsson S S
Biochem Biophys Res Commun. 1983 Oct 31;116(2):587-92. doi: 10.1016/0006-291x(83)90564-8.
Microsomal epoxide hydrolase activity, determined using benzpyrene 4,5-oxide and styrene 7,8-oxide, increased in cultured hepatocytes compared to freshly isolated cells. In contrast, cytosolic epoxide hydrolase activity, assayed using trans-stilbene oxide, had decreased 80% by 24 hr and was barely detectable after 96 hr in culture. There was no difference in enzyme activity between freshly isolated hepatocytes and the two rat hepatoma cell lines McA-RH 7777 and H4-II-E, when styrene 7,8-oxide was used as substrate. However, benzpyrene 4,5-oxide hydrolase activity of the McA-RH 7777 and H4-II-E cell lines were 55 and 10%, respectively, of freshly isolated hepatocytes. These results show that hepatoma cell lines provide a suitable system for studying the regulation of both the microsomal and cytosolic epoxide hydrolase enzymes.
与新鲜分离的细胞相比，使用苯并芘4,5 - 氧化物和苯乙烯7,8 - 氧化物测定的微粒体环氧化物水解酶活性在培养的肝细胞中有所增加。相反，使用反式二苯乙烯氧化物测定的胞质环氧化物水解酶活性在培养24小时后降低了80%，在培养96小时后几乎检测不到。当使用苯乙烯7,8 - 氧化物作为底物时，新鲜分离的肝细胞与两种大鼠肝癌细胞系McA - RH 7777和H4 - II - E之间的酶活性没有差异。然而，McA - RH 7777和H4 - II - E细胞系的苯并芘4,5 - 氧化物水解酶活性分别为新鲜分离肝细胞的55%和10%。这些结果表明，肝癌细胞系为研究微粒体和胞质环氧化物水解酶的调节提供了一个合适的系统。
