Toledo A, Ramani N, Rao C V
J Clin Endocrinol Metab. 1987 Aug;65(2):305-9. doi: 10.1210/jcem-65-2-305.
We previously reported that nuclei isolated from ovaries of premenopausal women contain binding sites for hCG/human LH (hLH). This study was undertaken to determine the possible functional significance of these nuclear binding sites. Upon addition to isolated ovarian (mostly luteal cells) nuclear membranes, hCG and hLH stimulated nucleoside triphosphatase (NTPase), an enzyme involved in nucleocytoplasmic transfer of mRNA, but not Mg2+-ATPase or NADH cytochrome c reductase activities, in a concentration-dependent manner. Heat-denatured hCG, isolated alpha- and beta-subunits of hCG, human FSH, PRL, and porcine relaxin had no effect on the enzyme. Addition of hCG antiserum blocked hCG's ability to stimulate NTPase activity. cAMP, which is a second messenger in hCG- and hLH-stimulated steroidogenesis, had no effect on NTPase activity. These results, which demonstrate that hCG acts on human ovarian nuclei directly, raise the possibility that internalized hCG might influence nuclear function(s) before it is eventually degraded in the lysosomes of ovarian cells.
我们之前报道过，从绝经前女性卵巢中分离出的细胞核含有hCG/人促黄体生成素（hLH）的结合位点。本研究旨在确定这些核结合位点可能的功能意义。将hCG和hLH添加到分离出的卵巢（主要是黄体细胞）核膜上后，它们以浓度依赖的方式刺激了核苷三磷酸酶（NTPase），该酶参与mRNA的核质转运，但对Mg2 + -ATP酶或NADH细胞色素c还原酶活性没有影响。热变性的hCG、分离出的hCGα和β亚基、人促卵泡生成素（FSH）、催乳素（PRL）和猪松弛素对该酶均无作用。添加hCG抗血清可阻断hCG刺激NTPase活性的能力。cAMP作为hCG和hLH刺激类固醇生成过程中的第二信使，对NTPase活性没有影响。这些结果表明hCG直接作用于人卵巢细胞核，这增加了内化的hCG在最终在卵巢细胞溶酶体中降解之前可能影响核功能的可能性。
