Feminization of the hepatic monooxygenases by growth hormone is mimicked by puromycin and correlates with a decrease in male-type cytochrome P450.
The hepatic monooxygenase system (MFO) was studied in hypophysectomized male rats treated with growth hormone (GH), puromycin, or both. GH significantly decreased the amount of cytochrome P450 and the activity of ethylmorphine demethylase but did not affect aniline hydroxylase or NADPH cytochrome c reductase. Puromycin significantly increased the activity of the reductase but otherwise had effects identical to GH. The agent's effects were additive. By labelling the P450 with [3H]-heme we found that GH decreased the amount of male-type (slow turnover) P450 by 56% but lowered the female-type (fast turnover) by only 10%. The hormone increased the half-life of both types by 56 and 100% respectively. We conclude that GH feminizes the MFO by decreasing the synthesis of male-type cytochrome P450.
D000815:Aniline Hydroxylase / Q000378:metabolism; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005037:Ethylmorphine-N-Demethylase / Q000378:metabolism; D013006:Growth Hormone / Q000494:pharmacology*; D007016:Hypophysectomy; D008099:Liver / Q000201:enzymology*; D008297:Male; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D011691:Puromycin / Q000494:pharmacology*; D051381:Rats; D012727:Sex Characteristics
D011691:Puromycin; D013006:Growth Hormone; D003577:Cytochrome P-450 Enzyme System; D000815:Aniline Hydroxylase; D005037:Ethylmorphine-N-Demethylase; D009251:NADPH-Ferrihemoprotein Reductase