Mineralocorticosteroids and pregnancy: regulation of extra-adrenal deoxycorticosterone production by estrogen.

During pregnancy, deoxycorticosterone (DOC) in maternal plasma is produced principally by 21-hydroxylation of circulating progesterone in a number of extra-adrenal tissues. Estrogen acts, directly or indirectly, to increase the transfer constant of conversion of progesterone to DOC. In this study, we evaluated the regulation of DOC production during pregnancy by considering the plasma levels of progesterone, the kinetics of extra-adrenal steroid 21-hydroxylase, and the stimulation of the conversion of progesterone to DOC by estrogen.