It has been reported that prostaglandins (PGs) stimulate steroidogenesis in the adrenal glands of various mammalian species. However, the exact role of PGs in steroidogenesis remains unclear. Therefore, attempts were made to clarify the action mechanism of PGs on steroidogenesis.
The production of 11-OHCS in adrenal cells was stimulated by ACTH, PGE₂ and PGF₂α. PGE₂ increased the c-AMP level, but PGF₂α had no effect on it. No effect was observed by indomethacin or theophylline on the production of 11-OHCS by ACTH. Cycloheximide inhibited the elevation in 11-OHCS by PGE₂ and PGF₂α. Different results were observed : PGs-combined effects of varying concentrations of ACTH were additive, PGs-combined effects of varying concentrations of dbc-AMP were synergic, and simultaneous incubation of maximal concentrations of ACTH and PGs failed to elicit a supramaximal response.
These results suggest that PGs act like ACTH on steroidogenesis in human and bovine adrenals and are in keeping with the hypothesis that the action of ACTH and PGs in steroidogenesis is Ca⁺⁺ influx in the adrenal cells.