Study of the direct effect of LHRH agonist on testicular 17-hydroxylase and 5 alpha-reductase activities in non-hypophysectomized adult rats treated with an anti-luteinizing hormone serum.
In order to study both direct and pituitary-mediated mechanisms of action of the LHRH analogue [D-Ser(TBU)6, des-Gly-NH2(10)]LHRH ethylamide upon testicular steroidogenesis in adult rat, we compared the effects of the agonist when administered alone or concomitantly with an anti-LH serum to non-hypophysectomized rats. Testicular steroid contents and in vitro progesterone and testosterone metabolism were determined. Anti-LH serum administration was able to prevent 5 alpha-reductase stimulation by the agonistic peptide, but not the inhibition of 17-hydroxylase activity. These data suggest that modulation of 17-hydroxylase involves both direct and pituitary-mediated processes, while 5 alpha-reductase stimulation is mainly if not only due to a pituitary-mediated mechanism.
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000378:metabolism*; D000818:Animals; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007016:Hypophysectomy; D007106:Immune Sera / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000276:immunology; D008297:Male; D010088:Oxidoreductases / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism*; D013250:Steroid Hydroxylases / Q000378:metabolism*; D013737:Testis / Q000201:enzymology*; D013739:Testosterone / Q000378:metabolism; D013997:Time Factors
D007106:Immune Sera; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D011374:Progesterone; D007986:Luteinizing Hormone; D010088:Oxidoreductases; D013250:Steroid Hydroxylases; D013254:Steroid 17-alpha-Hydroxylase; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase