Monget P, Besnard N, Huet C, Pisselet C, Monniaux D
INRA, Station de Physiologie de la Reproduction des Mammifères Domestiques, URA CNRS 1291, Nouzilly, France.
Horm Res. 1996;45(3-5):211-7. doi: 10.1159/000184790.
In the ovary, insulin-like growth factors (IGFs) enhance both proliferation and differentiation of follicular cells by potentiating gonadotropin's actions. The biological effects of IGFs are strikingly modulated by IGF-binding proteins (IGFBPs), whose levels in follicular fluid dramatically change during folliculogenesis. Indeed, in most mammalian species, follicular growth and atresia are characterized by an increase and a great decrease in the IGFBP-3/IGFBPs < 40 kD (IGFBP-2, -4 and -5) ratio in follicular fluid, respectively. These variations result from both changes in expression of these IGFBPs by follicular cells, and in local degradation by specific intrafollicular proteases. Such changes in IGFBP levels lead to great decrease and increase in IGF bioavailability in atretic and growing healthy follicles, respectively. Hence intrafollicular IGFBPs play a key role in the regulation of follicular development by modulating IGFs and therefore gonadotropin's actions.
在卵巢中，胰岛素样生长因子（IGFs）通过增强促性腺激素的作用来促进卵泡细胞的增殖和分化。IGF结合蛋白（IGFBPs）对IGFs的生物学效应有显著调节作用，其在卵泡液中的水平在卵泡发生过程中会发生显著变化。实际上，在大多数哺乳动物物种中，卵泡生长和闭锁的特征分别是卵泡液中IGFBP - 3/分子量小于40 kD的IGFBPs（IGFBP - 2、- 4和- 5）的比值增加和大幅降低。这些变化是由卵泡细胞对这些IGFBPs表达的改变以及卵泡内特定蛋白酶的局部降解共同导致的。IGFBP水平的这种变化分别导致闭锁卵泡和生长中的健康卵泡中IGF生物利用度大幅降低和增加。因此，卵泡内的IGFBPs通过调节IGFs进而调节促性腺激素的作用，在卵泡发育的调节中起关键作用。
