[Early effect of adrenalectomy and castration on the demethylating activity of the liver microsomal fraction in male rats].

The author examines three indices in liver microsomal fraction during the first five days after castration and adrenalectomy of male rats: demethylation in vitro of amidophen, amount of cytochrome P450 and cytochrome b5. Demethylating activity is lowered significantly to the respective control on the second day after adrenalectomy--73%, on the fifth day--61%; after castration on the third day--71%, on the fifth day--75%; after simultaneous castration and adrenalectomy after two days--53%, but on the fifth day--22%. The amount of cytochrome P450 diminishes parallely to the demethylating activity is due to the reduced amount of cytochrome P450, but the reduction of the latter is explained by the lowered activity of aminolevulanatsynthetase--the limiting enzyme in the synthesis of heme of cytochrome P450. Androgens and corticoids are inductors of microsomal oxidative enzymes and probably on the basis of this action the activity of aminoevulinatsynthetase is affected.