title: Renal cAMP and 1,25(OH)2D3 synthesis in estrogen-treated chick embryos and hens.
abstract: Onset of sexual maturity in female chickens or administration of estrogen to mature males or to juveniles of either sex results in increased parathyroid hormone (PTH)-dependent adenylate cyclase activity and increased 25-hydroxyvitamin D3-1-hydroxylase activity in kidney. The relationship between estrogen-mediated alterations of these two enzyme systems was investigated in embryonic and mature, egg-laying chickens treated in vivo with 17 beta-estradiol (E2). Basal and PTH- and forskolin-stimulated adenylate cyclase activity in kidney plasma membrane preparations was not affected by E2 treatment of 19-day-old chick embryos or of 41-wk-old egg-laying females. High, possibly maximal, levels of catalytic activity in control embryos and hens may have precluded further stimulation by E2. In contrast, E2 significantly enhanced 25-hydroxyvitamin D3-1-hydroxylase activity of embryonic kidney up to 10-fold (P less than 0.005). In mature females, E2 caused cessation of egg laying accompanied by a significant reduction (P less than 0.005) of 25-hydroxyvitamin D3-1-hydroxylase activity. These results indicate that the PTH-dependent adenylate cyclase and the 25-hydroxyvitamin D3-1-hydroxylase systems of avian kidney can be regulated independently and suggest that factors in addition to estrogen are involved in their regulation.
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002117:Calcitriol / Q000096:biosynthesis* / Q000378:metabolism; D002118:Calcium / Q000097:blood; D002642:Chick Embryo; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D005260:Female; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010281:Parathyroid Hormone / Q000494:pharmacology
chemical_list: D010281:Parathyroid Hormone; D005576:Colforsin; D004958:Estradiol; D000242:Cyclic AMP; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D000262:Adenylyl Cyclases; D002117:Calcitriol; D002118:Calcium