Immunological comparison of hepatic and extrahepatic cytochromes P-450.
Immunological comparison of hepatic and extrahepatic cytochromes P-450.
复制标题
肝脏和肝外细胞色素 P-450 的免疫学比较。
作者：
F. Guengerich;P. Mason
从苯巴比妥和3-甲基胆蒽处理的大鼠的肝微粒体制备两种明显同质的细胞色素P-450抗体;从未处理和苯巴比妥和3-甲基胆蒽处理的大鼠的肝、肺、肾、睾丸、脾、心脏、小肠、结肠、胃和脑制备微粒体组分。通过免疫扩散分析判断，在每个组织中观察到与两种抗体中的至少一种的交叉反应性。用除脾脏和结肠外的各组织制备的微粒体观察到苯并（a）芘羟化酶或7-乙氧基香豆素O-脱乙基酶活性的抑制;抑制曲线取决于所用底物和抗体以及制备微粒体的动物的预处理。一般而言，从3-甲基胆蒽处理的大鼠制备的微粒体最容易受到从3-甲基胆蒽处理的大鼠制备的肝微粒体中分离的细胞色素P-450抗体的抑制，苯巴比妥诱导也遵循相同的一般规则;然而，注意到几个例外情况。根据这些结果，肝外组织微粒体P-450通常与大鼠主要肝微粒体P-450在免疫学上相似。
Antibodies were raised to two apparently homogeneous cytochromes P-450 prepared from liver microsomes of phenobarbital- and 3-methylcholanthrene-treated rats; microsomal fractions were prepared from the livers, lungs, kidneys, testes, spleens, hearts, small intestines, colons, stomachs, and brains of untreated and phenobarbital- and 3-methylcholanthrene-treated rats. Cross reactivity was observed in each tissue with at least one of the two antibodies as judged by immunodiffusion analysis. Inhibition of benzo(a)pyrene hydroxylase or 7-ethoxycoumarin O-deethylase activity was observed with microsomes prepared from each tissue with the exception of spleen and colon; inhibition curves were dependent upon the substrate and antibody used as well as the pretreatment of the animals from which the microsomes were prepared. As a general rule, microsomes prepared from 3-methylcholanthrene-treated rats were inhibited most readily by antibody raised to cytochrome P-450 isolated from liver microsomes prepared from 3-methylcholanthrene-treated rats, and the same general rule held for phenobarbital induction; however, several exceptions were noted. On the basis of these results, the microsomal P-450s of extrahepatic tissues are, in general, immunologically similar to the major hepatic microsomal P-450s in the rat.