Alvares A P, Bickers D R, Kappas A
Proc Natl Acad Sci U S A. 1973 May;70(5):1321-5. doi: 10.1073/pnas.70.5.1321.
The CO-difference spectrum of microsomes from rats treated with the polychlorinated biphenyls mixture, Aroclor 1254, has an absorption maximum at 448 nm. With ethylisocyananide as the ligand for reduced microsomes, Aroclor 1254 treatment causes a shift in the 455-nm peak to 453 nm and increases the ratio of absorbance of 455 nm to that at 430 nm from 0.53, obtained with untreated rats, to 1.24. These findings are similar to those seen in rats treated with the polycyclic hydrocarbon, 3-methylcholanthrene, but differ from those that characterize cytochrome P-450 in control or phenobarbital-treated rats. Aroclor 1254 treatment results in a tripling of cytochrome P-448 content and a 10-fold increase in benzo-[a]pyrene hydroxylation. However-unlike 3-methylcholanthrene, but like the phenobarbital type of inducing agents-Aroclor 1254 treatment causes a significant enhancement of ethylmorphine N-demethylase. These data suggest that Aroclor 1254-induced cytochrome P-448 may be catalytically different from the 3-methylcholanthrene-induced P-448 or that the hemoprotein(s) induced by Aroclor 1254 may be a mixture of cytochromes P-448 and P-450 exhibiting catalytic properties of both cytochromes.
用多氯联苯混合物Aroclor 1254处理的大鼠微粒体的一氧化碳差光谱在448nm处有最大吸收峰。以乙基异氰化物作为还原微粒体的配体，Aroclor 1254处理导致455nm峰向453nm位移，并使455nm与430nm处吸光度之比从未经处理大鼠的0.53增加到1.24。这些发现与用多环烃3-甲基胆蒽处理的大鼠所见相似，但与对照或苯巴比妥处理的大鼠中细胞色素P-450的特征不同。Aroclor 1254处理导致细胞色素P-448含量增加两倍，苯并[a]芘羟基化增加10倍。然而，与3-甲基胆蒽不同，但与苯巴比妥类诱导剂一样，Aroclor 1254处理导致乙基吗啡N-脱甲基酶显著增强。这些数据表明，Aroclor 1254诱导的细胞色素P-448在催化作用上可能与3-甲基胆蒽诱导的P-448不同，或者Aroclor 1254诱导的血红蛋白可能是细胞色素P-448和P-450的混合物，表现出两种细胞色素的催化特性。
