Liu X, Andoh K, Yokota H, Kobayashi J, Abe Y, Yamada K, Mizunuma H, Ibuki Y
Department of Obstetrics and Gynecology, Gunma University School of Medicine, Maebashi, Japan.
Endocrinology. 1998 May;139(5):2342-7. doi: 10.1210/endo.139.5.5987.
The aim of this study was to investigate whether GH and insulin-like growth factor I (IGF-I) are involved in preantral folliculogenesis and, if so, to clarify the relationship between GH/IGF-I and activin/follistatin (FS) systems in immature female mice. Ovaries were obtained from 11-day-old mice, and preantral follicles, 100-105 microm in diameter, were mechanically isolated and selected for culture. Ten preantral follicles per well were cultured with different quantities and combinations of additives as follows: no additives (control), recombinant human FSH (rhFSH), IGF-I, recombinant human GH (rhGH), activin A, and recombinant human FS (rhFS). Mean diameters of the follicles were measured daily, and estradiol and immunoreactive inhibin levels in the cultured medium were assayed by RIA on day 4. rhGH showed stimulatory effects on the follicular diameter and the secretion of estradiol and immunoreactive inhibin. These effects were augmented by the presence of IGF-I and activin A. IGF-I alone did not show any stimulatory effect. The addition of rhFSH to activin A or to rhGH and activin A promoted preantral follicular growth and hormone production. On the other hand, GH- or activin-stimulated follicular growth was suppressed by rhFS in a dose-dependent manner. These results indicate that activin A and rhGH may play an important role in controlling earlier phases of follicular development during the infantile period, which is considered to be gonadotropin independent.
本研究的目的是调查生长激素（GH）和胰岛素样生长因子I（IGF-I）是否参与窦前卵泡发生，如果参与，阐明未成熟雌性小鼠中GH/IGF-I与激活素/卵泡抑素（FS）系统之间的关系。从11日龄小鼠获取卵巢，机械分离并挑选直径为100 - 105微米的窦前卵泡进行培养。每孔10个窦前卵泡用不同数量和组合的添加剂进行培养，如下：无添加剂（对照）、重组人促卵泡激素（rhFSH）、IGF-I、重组人生长激素（rhGH）、激活素A和重组人卵泡抑素（rhFS）。每天测量卵泡的平均直径，并在第4天通过放射免疫分析法测定培养基中雌二醇和免疫反应性抑制素水平。rhGH对卵泡直径以及雌二醇和免疫反应性抑制素的分泌具有刺激作用。IGF-I和激活素A的存在增强了这些作用。单独的IGF-I未显示任何刺激作用。将rhFSH添加到激活素A或rhGH与激活素A中可促进窦前卵泡生长和激素产生。另一方面，rhFS以剂量依赖性方式抑制GH或激活素刺激的卵泡生长。这些结果表明，激活素A和rhGH可能在控制婴儿期卵泡发育的早期阶段发挥重要作用，这一阶段被认为是不依赖促性腺激素的。
