Barañao J L, Bley M A, Batista F D, Glikin G C
Instituto de Biología y Medicina Experimental, (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina.
Biochem J. 1991 Jul 15;277 ( Pt 2)(Pt 2):557-60. doi: 10.1042/bj2770557.
Follicle-stimulating hormone (FSH), acting through a cycle AMP-mediated mechanism, promotes differentiation of rat granulosa cells cultured in a defined medium. Camptothecin, a DNA topoisomerase I blocker, inhibited the increase in progesterone and oestradiol production stimulated by FSH. This effect was not due to non-specific inhibition of protein synthesis, as shown by measurement of [35S]methionine incorporation. A transient increase in DNA topoisomerase I activity was observed after 24 h of culture in the presence of FSH or dibutyryl cyclic AMP. Our results are consistent with a key role for DNA topoisomerase I in the modulation of gene expression by FSH in rat granulosa cells.
促卵泡激素（FSH）通过环磷酸腺苷介导的机制发挥作用，促进在特定培养基中培养的大鼠颗粒细胞分化。喜树碱是一种DNA拓扑异构酶I抑制剂，它抑制了FSH刺激的孕酮和雌二醇生成的增加。如通过测量[35S]甲硫氨酸掺入量所示，这种作用并非由于对蛋白质合成的非特异性抑制。在存在FSH或二丁酰环磷酸腺苷的情况下培养24小时后，观察到DNA拓扑异构酶I活性出现短暂增加。我们的结果与DNA拓扑异构酶I在FSH调节大鼠颗粒细胞基因表达中起关键作用一致。
