Effect of growth hormone and ectopic transplantation of pituitary gland on sex-specific forms of cytochrome P-450 and testosterone and drug oxidations in rat liver.
The effects of growth hormone and ectopic transplantation of pituitary gland on the amounts of sex-specific cytochrome P-450, P-450-male and P-450-female, and the activities of testosterone and drug hydroxylases in male rat liver microsomes were studied. Hypophysectomy decreased the content of P-450-male, without changing the total cytochrome P-450 level. The continuous infusion of growth hormone into hypophysectomized rats and the transplantation of pituitary gland under the renal capsule caused a further decrease in P-450-male content and an expression of P-450-female. In contrast, the intermittent injection of growth hormone into hypophysectomized rats increased P-450-male content to the level seen in intact male rats. The activities of testosterone 2 alpha- and 16 alpha-, but not 6 beta-, 7 alpha-, or 15 alpha-hydroxylase, were changed in association with the level of P-450-male by these treatments. Anti-P-450-male immunoglobulin G inhibited testosterone 2 alpha- and 16 alpha-hydroxylations, but not 6 beta-, 7 alpha- or 15 alpha-hydroxylation. These results indicate that growth hormone regulates the expression of P-450-male responsible for testosterone 2 alpha- and 16 alpha-hydroxylations. The metabolism of 7-propoxycoumarin, benzo(a)pyrene and aminopyrine also changed with the content of P-450-male, although the correlation was less than that observed with testosterone 2 alpha- and 16 alpha-hydroxylation.
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D000072467:Cytochrome P450 Family 2; D005260:Female; D013006:Growth Hormone / Q000494:pharmacology*; D007016:Hypophysectomy; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D010084:Oxidation-Reduction; D010902:Pituitary Gland / Q000502:physiology / Q000637:transplantation*; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D039181:Steroid 16-alpha-Hydroxylase; D013739:Testosterone / Q000378:metabolism*
D013739:Testosterone; D013006:Growth Hormone; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C450279:CYP2C11 protein, rat; D000072467:Cytochrome P450 Family 2; D039181:Steroid 16-alpha-Hydroxylase