Ronco A M, Llanos M N, Valladares L E
Unidad de Biología de la Reproducción, Universidad de Chile, Santiago.
Steroids. 1993 Jul;58(7):314-9. doi: 10.1016/0039-128x(93)90090-a.
The effect of human chorionic gonadotropin (hCG) on intact Leydig cell phospholipid methylation was studied. Hormonal stimulation of rat Leydig cells increased the incorporation of [methyl-3H]methionine into phospholipids threefold. This effect was observed after 10 minutes of incubation time and was time and dose dependent with a maximal stimulation at 67 ng/ml of hCG. In the presence of hCG, 3H-labeled methyl groups were preferentially incorporated into phosphatidyl-N-monomethylethanolamine. This effect of hCG was not reproduced by dibutyryl cyclic adenosine monophosphate (cAMP), cholera toxin, or forskolin. Purified hCG beta subunit but not hCG alpha subunit had stimulatory activity on Leydig cell phospholipid methylation. We conclude that luteinizing hormone (LH)/hCG stimulates specifically Leydig cell phospholipid methylation, because LH-releasing hormone or [Arg8]-vasopressin did not modify these reactions. We postulate that these reactions are occurring at a cellular level that involves hormone-receptor interaction. It is also suggested that this biological response involves hCG beta subunit receptor interaction and does not require cAMP synthesis.
研究了人绒毛膜促性腺激素（hCG）对完整睾丸间质细胞磷脂甲基化的影响。对大鼠睾丸间质细胞进行激素刺激后，[甲基 - ³H]甲硫氨酸掺入磷脂的量增加了三倍。孵育10分钟后观察到这种效应，且具有时间和剂量依赖性，在hCG浓度为67 ng/ml时刺激作用最大。在hCG存在的情况下，³H标记的甲基优先掺入磷脂酰 - N - 单甲基乙醇胺。二丁酰环磷酸腺苷（cAMP）、霍乱毒素或福斯高林不能重现hCG的这种效应。纯化的hCGβ亚基而非hCGα亚基对睾丸间质细胞磷脂甲基化具有刺激活性。我们得出结论，促黄体生成素（LH）/hCG特异性刺激睾丸间质细胞磷脂甲基化，因为促性腺激素释放激素或[精氨酸⁸]加压素不会改变这些反应。我们推测这些反应发生在涉及激素 - 受体相互作用的细胞水平。还表明这种生物学反应涉及hCGβ亚基受体相互作用，且不需要cAMP合成。
