Testicular steroid metabolism in juvenile bank voles (Clethrionomys glareolus Schreber) exposed to different photoperiods: an in vitro study.
Juvenile male bank voles (18-22 days of age) were either sacrificed immediately (Group C) or subjected first to a long (18L:6D, lights on 0600-2400; Group L) or a short (6L:18D, lights on 0800-1400; Group S) photoperiod for 1 week. The animal were killed by decapitation, the gonads were excised, and minced, and the conversion of [4-14C]pregnenolone (delta 3P) and [4-14C]dehydroepiandrosterone (DHA) to metabolites was studied in vitro. The radioactive steroids formed were separated and identified by thin-layer chromatography (TLC). The conversion of delta 3P to C19-steroids increased markedly from 35 (Group C) to 86% (Group L) during the first week in the long photoperiod whereas in the short photoperiod a decrease to 14.42% (Group S) was observed. The reduced production of C19-steroids in the more inactive testes was accompanied by the accumulation of progesterone (delta 4P) (52.98% Group S and 24.9% Group C) and small amounts of 17 alpha-hydroxyprogesterone (17 alpha-OH-delta 4P) (2.5 and 4.5%, respectively), whereas in Group L only trace amounts of these metabolites were encountered. No marked differences in the metabolism of [4-14C]DHA between the photoperiodic groups were observed. These results seem to indicate that at least in vitro marked changes in C17-C20-lyase and/or 17 alpha-hydroxylase activities occur in this seasonally breeding species during testicular maturation and photoperiodically induced regression.
D000728:Androgens / Q000378:metabolism*; D000818:Animals; D003411:Arvicolinae / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D003687:Dehydroepiandrosterone / Q000378:metabolism; D008027:Light; D008297:Male; D010507:Periodicity; D011284:Pregnenolone / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D013737:Testis / Q000378:metabolism / Q000528:radiation effects*
D000728:Androgens; D003687:Dehydroepiandrosterone; D011374:Progesterone; D011284:Pregnenolone