CONCENTRATION OF PROSTAGLANDIN F2α AND STEROIDS IN THE HUMAN CORPUS LUTEUM

Abstract

SUMMARY The concentration of prostaglandin F_2α (PGF_2α), progesterone, pregnenolone, oestradiol-17β, oestrone, androstenedione and testosterone was measured in corpora lutea obtained from 40 women at various stages of the menstrual cycle. The concentration of PGF_2α was significantly higher in corpora lutea immediately after ovulation (26·7 ± 3·9 (s.e.m.) ng/g, P < 0·005) and in corpora albicantia (16·3 ± 3·3 ng/g, P < 0·005) than at any other time during the luteal phase. There was no correlation between the concentration of PGF_2α and that of any steroid. The progesterone concentration was highest in corpora lutea just after ovulation (24·9 ± 6·7 μg/g) and in early luteal groups (25·7 ± 6·8 μg/g) but declined significantly (P < 0·05) to its lowest level in corpora albicantia (1·82 ± 0·66 μg/g). The concentration of oestradiol-17β in the corpus luteum and luteal weight were significantly greater during the mid-luteal phase than at any other stage (concentration 282 ± 43 ng/g, P < 0·05; weight 1·86 ± 0·18 g, P < 0·005). The results indicate that regression of the human corpus luteum is not caused by a rise in the ovarian concentration of PGF_2α in the late luteal phase of the cycle.