Hormonal profile after removal of the dominant follicle and corpus leteum in women.

Abstract

The present experiments were performed to elucidate the mechanism of the selection and maturation of a dominant follicle in women. Eight normally menstruating women undergoing myonectomy or tubal surgery volunteered for the present study. In 3 patients who were operated on Day 9-11, a visual dominant follicle was removed. The other 5 patients underwent the removal of a newly developing corpus luteum on Day 15-21. After taking 3 or 4 preoperative blood samples in the morning after their hospitalization, blood was obtained at 3 or 6 h intervals for the first 36-45 h and at 1-3 day intervals thereafter for 21-34 days. Serum FSH, LH, estradiol and progesterone were measured by radioimmunoassay. Follicleectomy was followed by a sudden drop in estradiol and a minor increase in progesterone. FSH increased for a few days and then declined. There was a drastic, but short-term increase in LH following follicleectomy which was performed before a preovulatory gonadotropin surge. A LH surge occurred 10.7 +/- 1.2 days (mean +/- S.E.) after follicular ablation followed by a luteal phase. In contrast, there was no remarkable LH release in 4 out of 5 patients who underwent luteectomy. A slightly higher level of FSH was sustained for 2-7 postoperative days. "Luteal phase" rises in estradiol and progesterone terminated promptly following luteectomy. A LH surge was observed 14.2 +/- 1.7 days after surgery followed by a luteal phase. After either type of operation, a sustained increase in FSH was followed by a gradual increase in estradiol which preceded a gonadotropin surge. These hormonal sequences resemble those seen in the normal follicular phase. The present data demonstrated that follicleectomy and luteectomy bring on some characteristic hormonal changes which may exert stimulatory or suppressive effects on the selection and maturation of a dominant follicle after the removal of a main ovarian cyclic structure culminating in ovulation at a certain interval.

Local Delivery of Angiopoietin-2 into the Preovulatory Follicle Terminates the Menstrual Cycle in Rhesus Monkeys1

“…Laparoscopy of one animal 10 days post-treatment confirmed the disappearance of the injected follicle and the appearance of another large antral follicle on the contralateral ovary. The hormonal patterns and emergence of another single ovulatory follicle within 12-14 days (i.e., the normal interval of the follicular phase) are remarkably similar to those observed in monkeys and women after ablation of the dominant structure (preovulatory follicle or corpus luteum) or removal of the ovary bearing the dominant structure during natural menstrual cycles [41][42][43][44]. The current data suggest that ANGPT2 treatment is comparable to physically removing the preovulatory follicle, thereby eliminating the dominant structure on the ovary and resetting the ovarian cycle to allow the selection and maturation of the next dominant follicle with timely ovulation and luteinization 2 wk later.…”

Physiologic Basis of Ovulation Induction

“…2 As a consequence of successive recruitments, the ovaries appear always to contain a pool of small Graafian follicles from which a prospective dominant follicle can be selected. 3 ' 4 Once selected, a dominant follicle typically grows and develops to the preovulatory state. Those follicles that are not selected are destroyed in a programmed cell-death mechanism called apoptosis.…”