19-Acetylenic-deoxycorticosterone inhibits 19-hydroxylase and 11 beta-hydroxylase activities in dispersed bovine zona fasciculata cells.

19-Acetylenic-deoxycorticosterone (19-A-DOC) is believed to be a competitive irreversible inhibitor of the synthesis of 19-nor-deoxycorticosterone (19-nor-DOC), a potent mineralocorticoid implicated in some forms of human and animal hypertension. It has been shown to inactivate 11 beta/19-hydroxylase in hamster adrenal mitochondria. Dispersed bovine zona fasciculata cells were incubated for one hour with 1.5 x 10(-8) M ACTH and 0, 1, 10, or 100 microM 19-A-DOC and tritiated deoxycorticosterone (DOC) substrate. Steroids were separated using two sequential thin-layer chromatography systems and their tritium content was counted and corrected for recovery. The 19-A-DOC decreased synthesis of 19-hydroxydeoxycorticosterone, the precursor of 19-nor-DOC. The inhibitor also impaired 11-hydroxylation of DOC to form corticosterone. The data suggest that 19-A-DOC is an effective inhibitor of 11 beta/19-hydroxylase activity in dispersed bovine adrenal cells.