Studies on ovarian and adrenal steroids at different phases of the menstrual cycle. III. Steroid and lutropin levels before and after the administration of a single contraceptive dose of depot-medroxyprogesterone acetate (DMPA).

Ovarian and adrenal steroids and biologically active lutropin were measured in peripheral plasma samples obtained from 5 normally menstruating women. Plasma samples were collected every 3 h for a period of 39 hours in the periovulatory period of a pretreatment (control) cycle and then 16 and 54 days after a single i.m. injection of 150 mg of depot-medroxyprogesterone acetate (DMPA). Sixteen days after DMA administration, the levels of estradiol, progesterone, 17-hydroxyprogesterone, and lutropin were reduced to early follicular phase levels. No further decrease was found in 17-hydroxyprogesterone and lutropin levels; however an additional decrease occurred in the levels of estradiol and in the "morning" levels of progesterone 54 days after the administration of DMPA. Furthermore, the levels of pregnenolone, androstenedione, testosterone and dihydrotestosterone were significantly diminished in all samples collected after the administration of DMPA. Fifty-four days following the administration of DMPA, the levels of cortisol and 17-hydroxypregnenolone were significantly reduced. The administration of DMPA did not interfere with the circadian rhythm of cortisol, pregnenolone, 17-hydroxypregnenolone, dehydroepiandrosterone, 17-hydroxyprogesterone, and androstenedione levels. A significant circadian rhythm was also found in testosterone (after 16 days) and lutropin (after 54 days) levels. No circadian variation was found in estradiol, progesterone and dihydrotestosterone levels.