Production rate of deoxycorticosterone in women during the follicular and luteal phases of the ovarian cycle: the role of extraadrenal 21-hydroxylation of circulating progesterone in deoxycorticosterone production.

The fractional conversion of plasma progesterone to deoxycorticosterone (DOC) ([rho]BU P-DOC) has been determined in pregnant, nonpregnant, and adrenalectomized women and men. The [rho]BU P-DOC varies widely among persons, but the [rho]BU P-DOC in a given subject is invariant regardless of plasma progesterone concentrations. In the present investigation we sought to ascertain 1) the production rate of DOC (PR-DOC) during the follicular and luteal phases of the ovarian cycle of women and 2) the role of extraadrenal 21-hydroxylation of progesterone as a source of DOC during the luteal phase of the ovarian cycle. Four subjects were given iv infusions of [3H]progesterone and [14C]DOC in order to determine [rho]BU P-DOC and the PR-DOC during both phases of the ovarian cycle. The [rho]BU P-DOC found in these subjects were within the range of values previously reported, viz. 0.007 +/- 0.001 (mean +/- SEM), and did not change during the cycle. The mean daily PR-DOC in these subjects during the follicular phase of the menstrual cycle was 58 microgram/24 h, whereas the mean daily PR-DOC during the luteal phase was 318 microgram/24 h. In each subject the PR-DOC during the luteal phase was 4--7 times greater than the PR-DOC during the follicular phase of the cycle. The increase in plasma concentrations of DOC during the luteal phase of the ovarian cycle apparently results from extraadrenal formation of DOC from circulating progesterone.