Ovarian steroid secretion in normally menstruating women II. The contribution of the corpus luteum

A clinical study was conducted using plasma samples from 9 normally menstruating women volunteers to determine the contribution of the corpus luteum on the steroid profile. The levels of 12 unconjugated steroids and 4 steroid sulphates were analyzed in the peripheral circulation and in the venous blood draining both ovaries before and after surgical removal of a freshly formed corpus luteum. Peripheral levels of several steroids were also measured during 3 preoperative and 3 postoperative days. Levels of certain of the steroids were significantly higher in the venous blood draining the "active" ovary (containing the corpus luteum) than in the blood draining the "inactive" ovary. The levels of many of the steroids were significantly higher in the blood draining both ovaries than in the perpheral blood but some of the steroid levels were only higher in the blood draining the active ovary. Enucleation of the corpus luteum abolished the previous differences in steroid levels between the 2 ovaries and diminished certain steroid levels and raised others in the blood draining the ovary from which the corpus luteum had been removed. The most important steroids secreted by the human corpus luteum are concluded to be progesterone 20a-dihydroprogesterone 17-hydroxyprogesterone estradiol and estrone.