Liu Y X, Peng X R, Liu K, Ny T
State Key Laboratory of Reproductive Biology, Academia Sinica, Beijing, PRC.
Sci China B. 1994 Mar;37(3):271-9.
In the present study, gonadotropin and gonadotropin-releasing hormone (GnRH) regulation of tPA and PAI-1 expression in PMSG-primed granulosa cells has been investigated. (i) Addition of gonadotropins (FSH and LH) and GnRH agonist (GnRHa) or PMA to the culture increases tPA activity; FSH (or LH) plus GnRHa (or PMA) in the culture further enhances the enzyme production to such an extent that a more obvious effect than the additive effect caused by these hormones used alone has been observed; (ii) in contrast, FSH and LH decrease PAI-1 activity, whereas GnRHa and PMA alone markedly increase PAI-1 mRNA level and PAI-1 activity. Because FSH and LH stimulate tPA production and have no significant effect on PAI-1 mRNA induction, the observed inhibition of PAI-1 activity by gonadotropins may be due to the occurrence of neutralization of PA and PAI-1 proteins in the conditioned media by the formation of complexes between PA and PAI-1; (iii) increases in PAI-1 mRNA level and activity by GnRH and PMA are completely inhibited by the co-addition of FSH or LH to the culture. It is, therefore, suggested that the mechanism of gonadotropin and GnRHa regulation of tPA and PAI-1 expression in granulosa cells is different.
在本研究中，已对促性腺激素和促性腺激素释放激素（GnRH）对孕马血清促性腺激素（PMSG）预处理的颗粒细胞中组织型纤溶酶原激活物（tPA）和纤溶酶原激活物抑制剂-1（PAI-1）表达的调节作用进行了研究。（i）向培养物中添加促性腺激素（促卵泡激素和促黄体生成素）、GnRH激动剂（GnRHa）或佛波酯（PMA）可增加tPA活性；培养物中促卵泡激素（或促黄体生成素）加GnRHa（或PMA）可进一步增强酶的产生，以至于观察到的效果比单独使用这些激素产生的相加效应更明显；（ii）相反，促卵泡激素和促黄体生成素降低PAI-1活性，而单独的GnRHa和PMA则显著增加PAI-1 mRNA水平和PAI-1活性。由于促卵泡激素和促黄体生成素刺激tPA产生，且对PAI-1 mRNA诱导无显著影响，因此促性腺激素对PAI-1活性的观察到的抑制作用可能是由于在条件培养基中PA和PAI-1蛋白通过形成PA与PAI-1之间的复合物而发生中和；（iii）向培养物中共同添加促卵泡激素或促黄体生成素可完全抑制GnRH和PMA引起的PAI-1 mRNA水平和活性的增加。因此，提示促性腺激素和GnRHa对颗粒细胞中tPA和PAI-1表达的调节机制不同。
