Yeh John, Kim Beomsu
Department of Gynecology, University at Buffalo, State University of New York, Buffalo, New York 14222, USA.
Reprod Sci. 2007 Jan;14(1):10-9. doi: 10.1177/1933719106298186.
Reproductive aging results in declines in female fertility and in slight declines in baseline serum inhibins in humans. The authors tested the hypothesis that exogenous ovarian stimulation as a noninvasive dynamic test, by amplifying inhibin levels, can define more accurately than baseline serum inhibin levels the ovarian age of female rats. Female rats--young (immature, 26 days old), adult (65-75 days old), and reproductively aged (8- to 9-month-old retired breeders)--were administered pregnant mare's serum gonadotropin to stimulate the ovaries and the serum inhibin A and inhibin B, and ovarian inhibins were measured. The young and adult females had at least a 4- to 10-fold increase in serum inhibin A and inhibin B after ovarian stimulation, but the reproductively aged females did not. Adult female serum inhibin measurements after stimulation at every stage of the estrous cycle revealed a consistent 4- to 5-fold increase in all stages, whereas the reproductively aged females did not. Western blot analyses of ovarian lysates were consistent with the serum inhibin level results and revealed that ovarian inhibin alpha, inhibin beta A, and inhibin beta B subunit levels in adult ovaries were elevated after ovarian stimulation but not in the reproductively aged ovaries. The data presented here demonstrate that young, adult, and reproductively aged female inhibin responses after exogenous ovarian stimulation were different. Inhibin measurement in serum after ovarian challenge in rats, therefore, is a noninvasive method that could be used to dissect ovarian function in aging in more detail.
生殖衰老会导致女性生育能力下降，且人类的基础血清抑制素水平也会略有下降。作者测试了这样一个假设，即作为一种非侵入性动态测试的外源性卵巢刺激，通过放大抑制素水平，比基础血清抑制素水平能更准确地界定雌性大鼠的卵巢年龄。对雌性大鼠——幼年（未成熟，26日龄）、成年（65 - 75日龄）和生殖衰老（8至9月龄的退役繁殖鼠）——注射孕马血清促性腺激素以刺激卵巢，并测量血清抑制素A和抑制素B以及卵巢抑制素。幼年和成年雌性大鼠在卵巢刺激后血清抑制素A和抑制素B至少增加了4至10倍，但生殖衰老的雌性大鼠没有。在发情周期的每个阶段刺激后对成年雌性大鼠血清抑制素的测量显示，所有阶段都有一致的4至5倍增加，而生殖衰老的雌性大鼠则没有。卵巢裂解物的蛋白质印迹分析与血清抑制素水平结果一致，显示成年卵巢中卵巢抑制素α、抑制素βA和抑制素βB亚基水平在卵巢刺激后升高，但生殖衰老的卵巢中没有。此处呈现的数据表明，外源性卵巢刺激后，幼年、成年和生殖衰老的雌性大鼠的抑制素反应不同。因此，大鼠卵巢刺激后血清抑制素的测量是一种可用于更详细剖析衰老过程中卵巢功能的非侵入性方法。
