各種動物の副腎遊離細胞におけるステロイド産生に及ぼすカルシウムの影響
スポンサーリンク
概要
- 論文の詳細を見る
Birmingham et al. first demonstrated that calcium was required during the steroidogenic action of ACTH. Farese demonstrated that calcium had no effect on steroidogenesis in rat adrenal slices unless ACTH or cyclic AMP was present, while Kako reported that 11-OHCS was produced by calcium alone in human isolated adrenal cells in the absence of ACTH or dibutyryl cyclic AMP (dbc-AMP). The present work was performed in an attempt to examine how calcium stimulates steroidogenesis in iso-lated adrenal cells of various animals.<BR>Isolated adrenal cells of various animals (rats, rabbits, dogs and cattle) were prepaed by the modification of Sayers' method. They were incubated in the medium of Krebs-Ringer bicarbonate buffer, which contained various doses of calcium, ACTH or dbcAMP, at 37°C for 2 hours under a gas mixture of 95%O<SUB>2</SUB>-5%CO<SUB>2</SUB>. Steroid production was estimated by the method of Silber et al.<BR>11-OHCS was produced by dbc-AMP, but not produced by ACTH in isolated adrenal cells of all animals in the absence of calcium. 11-OHCS production by 250 μg of dbc-AMP was less than that by 800 pg of ACTH in dog adrenal cells, but in other animals the former was more than the latter. Calcium alone was able to produce 11-OHCS in all animals. 11-OHCS production by calcium alone was less in rat adrenal cells than in other animals.<BR>In dog adrenal cells cycloheximide partially blocked 11-OHCS synthesis by calcium.<BR>These data suggest that adenyl cyclase of adrenocortical cells may be stimulated by calcium alone, supporting the hypothesis that calcium is a second messenger of ACTH.
- 日本内分泌学会の論文