Barnett Deborah K, Abbott David H
Wisconsin Primate Research Center, University of Wisconsin, Madison, Wisconsin 53715, USA.
Am J Hum Biol. 2003 May-Jun;15(3):296-319. doi: 10.1002/ajhb.10149.
During the ovarian or menstrual cycle, prior to ovulation, many female primates exhibit a relatively prolonged follicular phase and terminate the postovulatory luteal phase with menstrual bleeding. The prolonged follicular phase is a trait that distinguishes primate from nonprimate species. It enables extended estrogen-induced proliferation and growth of the uterine endometrium prior to progesterone-induced maturation during the luteal phase to accommodate a potential pregnancy with a rapidly invading placenta. Progressive development of both an extended duration of estrogen-induced, preimplantation endometrial proliferation and a rapidly invading placenta across the Primate order may well have been necessary to accommodate differentiation and growth of an increasingly large fetal brain. Prolongation of the follicular phase in primates has also led to the isolation of the final stages of follicle selection (growth deviation of the dominant follicle from its contemporaries) solely within the follicular phase and thus outside the protection of luteal phase progesterone inhibition of pituitary luteinizing hormone (LH) secretion. Such primate reproductive characteristics put the latter stages of ovarian follicle selection at risk of exposure to excessive pituitary secretion of LH. Excessive secretion of LH during follicle selection could result not only in impaired follicle development, excessive ovarian androgen secretion, and ovulation failure, but also in excessive estrogenic stimulation of the uterine endometrium without intervening menstrual periods. Such reproductive abnormalities are all found in a single, prevalent infertility syndrome afflicting women in their reproductive years: polycystic ovary syndrome (PCOS). We propose that successful female reproductive adaptations to accommodate the growth demands of large-brained primate fetuses have facilitated a particular vulnerability of higher primates to hypergonadotropic disruption of ovulatory function, as found in PCOS.
在卵巢或月经周期中，排卵前，许多雌性灵长类动物会经历相对较长的卵泡期，并在排卵后的黄体期以月经出血结束。延长的卵泡期是灵长类动物区别于非灵长类动物的一个特征。它能使子宫内膜在黄体期孕酮诱导成熟之前，在雌激素诱导下进行更长时间的增殖和生长，以适应快速侵入的胎盘可能带来的妊娠。在整个灵长目动物中，雌激素诱导的植入前子宫内膜增殖时间延长以及胎盘快速侵入的逐步发展，很可能是适应日益增大的胎儿大脑分化和生长所必需的。灵长类动物卵泡期的延长还导致卵泡选择的最后阶段（优势卵泡与其同时期卵泡的生长偏差）仅在卵泡期内发生，因此处于黄体期孕酮抑制垂体促黄体生成素（LH）分泌的保护之外。这种灵长类动物的生殖特征使卵巢卵泡选择的后期阶段面临垂体过度分泌LH的风险。卵泡选择期间LH分泌过多不仅会导致卵泡发育受损、卵巢雄激素分泌过多和排卵失败，还会导致子宫内膜受到过多雌激素刺激而无月经间期。这些生殖异常都出现在一种影响育龄女性的常见不孕症综合征中：多囊卵巢综合征（PCOS）。我们认为，雌性灵长类动物为适应大脑袋胎儿的生长需求而成功进行的生殖适应性变化，导致了高等灵长类动物对排卵功能的高促性腺激素性破坏特别敏感，就像在PCOS中所发现的那样。
