Early follicle growth in the juvenile macaca monkey ovary: the effects of estrogen priming and follicle-stimulating hormone.
The mechanism(s) that drives preantral and early antral follicle growth in the primate ovary is poorly understood. We previously reported that estrogen does not stimulate preantral or early antral follicle growth in juvenile primates. The purpose of the present study was to determine whether estrogen priming may play a role in enhancing FSH-stimulated follicle growth. Eight juvenile monkeys received implants on Day 1 of silastic capsules containing estradiol (or vehicle) to elevate circulating estradiol levels. Daily FSH injections were initiated on Day 4 and continued for up to 12 days. The left ovary was removed on Day 8 and served as a control. Ovulation was induced, and a luteal phase followed. On the first day of menses, the estradiol (vehicle) capsule-FSH protocol was repeated. The remaining ovary was removed on Day 8 of the second cycle. The number and size of all follicles in both ovaries were evaluated by light microscopy. Results indicate that estrogen priming in the first cycle did not enhance growth of preantral or antral follicles, but did result in fewer developing follicles > 1.0 mm in diameter, this was accompanied by an increase in early atretic antral follicles of similar size. In the second cycle, an even further reduction in number and size of developing antral follicles > 1.0 mm in diameter was observed. These data suggest that pretreatment with exogenous estrogen has an anti-follicular action on follicle growth in these primates.
Koering
M J
MJ
Department of Anatomy, George Washington University, District of Columbia 20037.
Danforth
D R
DR
Hodgen
G D
GD
D000818:Animals; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D008252:Macaca fascicularis / Q000254:growth & development*; D006080:Ovarian Follicle / Q000187:drug effects / Q000254:growth & development*; D010053:Ovary / Q000187:drug effects / Q000254:growth & development*
D004958:Estradiol; D005640:Follicle Stimulating Hormone