Photoperiod-induced changes in the testicular metabolism of [4-14C]17 alpha-hydroxyprogesterone in the bank vole (Clethrionomys glareolus).
Minces of the testes of bank voles, born and reared in a long (18L:6D) photoperiod until weaning (18-22 days of age) and subjected thereafter to a short (6L:18D, Group S) or a long (18L:6D, Group L) photoperiod for 6-9 weeks, were incubated with [4-14C]17 alpha-hydroxyprogesterone in the presence of cofactors (NADP/NADPH, 1.3 mmol/1) for 1 h at 37 degrees C. The radioactive metabolites were characterized and identified by thin-layer chromatography with derivative formation and chromatography to constant specific activity and isotope ratio. In Group L virtually all of the substrate was utilized and it was readily converted to androgens (48% of the radioactivity recovered) such as androstenedione and testosterone. The only pregnane metabolite identified was 17 alpha-hydroxy,20 alpha-dihydroxyprogesterone (43.3%). In Group S there was a decreased production of 17 alpha-hydroxy,20 alpha-dihydroprogesterone and androgens (25.4% and 10.4% respectively) and a substantial portion of the substrate was not metabolized (38.8%). The main androgen metabolites identified, androst-4-ene-3 beta,17 beta-diol and 5 alpha-androstane-3,17-dione are hormonally quite inert steroids. No androstenedione or testosterone was found. The results indicate that exposure to short photoperiod induces a decrease in the testicular C17-C20 lyase and 20 alpha-hydroxysteroid dehydrogenase.
D019326:17-alpha-Hydroxyprogesterone; D000728:Androgens / Q000378:metabolism; D000818:Animals; D003411:Arvicolinae; D006908:Hydroxyprogesterones / Q000378:metabolism* / Q000494:pharmacology; D066298:In Vitro Techniques; D008027:Light; D008297:Male; D011278:Pregnanes / Q000378:metabolism; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism; D013737:Testis / Q000378:metabolism*
D000728:Androgens; D006908:Hydroxyprogesterones; D011278:Pregnanes; D019326:17-alpha-Hydroxyprogesterone; D013254:Steroid 17-alpha-Hydroxylase