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 compe titive irreversible inhibitor of the synthesis of 19-nor-deoxycorticos terone (19-nor-DOC), a potent mineralocorticoid implicated in some for ms of human and animal hypertension. It has been shown to inactivate 1 1 beta/19-hydroxylase in hamster adrenal mitochondria. Dispersed bovin e zona fasciculata cells were incubated for one hour with 1.5 X 10(-8) M ACTH and 0, 1, 10, or 100 mu M 19-A-DOC and tritiated deoxycorticos terone (DOC) substrate. Steroids were separated using two sequential t hin-layer chromatography systems and their tritium content was counted and corrected for recovery. The 19-A-DOC decreased synthesis of 19-hy droxydeoxycorticosterone, the precursor of 19-nor-DOC. The inhibitor a lso impaired 11-hydroxylation of DOC to form corticosterone. The data suggest that 19-A-DOC is an effective inhibitor of 11 beta/19-hydroxyl ase activity in dispersed bovine adrenal cells.