Development of Graafian Follicles in Adult Human Ovary. I. Correlation of Estrogen and Progesterone Concentration in Antral Fluid with Growth of Follicles1
Radioimmunoassays of progesterone, estradiol-17β and estrone were performed on antral fluids aspirated from ovaries in situ or from individual follicles dissected out of excised ovaries during different phases of the menstrual cycle of women. A marked increase in progesterone was observed in samples of antral fluid aspirated from ovaries in situ during late proliferative phase (days 10–14), 790–1080 pg/μl, compared to early proliferative phase (days 4–9), 154–366 pg/μl. Estradiol-17β concentrations (983–1355 pg/μl) were also elevated during late proliferative phase and reached a peak on day 12. Estrone levels were 2–3 times lower than those of estradiol-17β. There was a progressive overall increase in the steroid concentration of antral fluids of individual follicles related to their growth during proliferative phase. Progesterone concentration was relatively increased in follicles of 7–8 mm diameter. The level rose sharply in the larger follicles (11–21 mm) during late proliferative phase. Estrone concentration increased progressively with follicular growth. No marked elevation in estradiol-17β levels occurred until the follicles were very large in size (14–21 mm). During the secretory phase, follicles larger than 9–10 mm were not normally found and the steroid levels in antral fluid gradually declined with the progression of the menstrual cycle.