Effects of estradiol on aldosterone secretion in ovariectomized rats

The effects and action mechanisms of estradiol on aldosterone secretion in female rats were studied. Replacement of estradiol benzoate (EB) increased the levels of plasma estradiol and aldosterone in ovariectomized (Ovx) rats . The aldosterone release from zona glomerulosa (ZG) cells was higher in EB -treated rats than in oil-treated animals. EB treatment potentiated the res ponses of aldosterone release to adrenocorticotropic hormone (ACTH), forsko lin (FSK), and 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP). Adm inistration of EB in vivo did not alter cAMP production in response to ACTH or FSK. Although angiotensin II (Ang II) increased aldosterone secretion b y rat ZG cells, the stimulatory effect of Ang II on the release of aldoster one was not altered by EB treatment. The conversions of [H-3]-deoxycorticos terone to [H-3]-corticosterone and [H-3]-corticosterone to [H-3]-aldosteron e in EB-treated groups were greater than those in the oil-treated group. Th ese results suggest that estradiol increases aldosterone secretion in part through the mechanisms involving the activation of the post-cAMP pathway, 1 1 beta-hydroxylase and aldosterone synthase activity. J. Cell. Biochem. 73: 137-144, 1999. (C) 1999 Wiley-Liss, Inc.