Department of Surgery, Taipei City Hospital, Taiwan, Republic of China.
Free Radic Res. 2012 Jun;46(6):718-25. doi: 10.3109/10715762.2012.669835. Epub 2012 Mar 20.
Rat granulosa cells (GCs) were treated with human chorionic gonadotropin (hCG), 8-bromo-adenosine 3',5'-cyclic monophosphate (8-Br-cAMP), forskolin, phorbol 12-myristate 13-acetate (PMA), A23187 or pregnenolone in the absence or presence of hydrogen peroxide (H(2)O(2)). Different doses of trilostane were applied to GCs treated with steroidogenic precursors, that is, 25-hydroxy-cholesterol (25-OH-C) in the absence or presence of H(2)O(2). Results showed that all of the chemicals stimulated the progesterone (PG) release from rat GCs, but the stimulatory effects were inhibited by H(2)O(2) dose-dependently. 25-OH-C stimulated the PG release, which was inhibited by H(2)O(2) in the presence of trilostane. H(2)O(2) attenuated steroidogenic acute regulatory (StAR) protein expression, but did not alter the expression of cytochrome P450 side chain cleavage (P450scc) in Western blotting. This study indicated that H(2)O(2) inhibited PG production by GCs via cAMP pathway, protein kinase C (PKC) and the activities of intracellular calcium, P450scc and StAR protein.
大鼠颗粒细胞（GCs）用人绒毛膜促性腺激素（hCG）、8-溴-腺苷 3'，5'-环单磷酸（8-Br-cAMP）、佛司可林、十四烷酰佛波醇 12-乙酸酯（PMA）、A23187 或孕烯醇酮处理，同时存在或不存在过氧化氢（H2O2）。不同剂量的三氯司坦应用于用甾体生成前体处理的 GCs，即 25-羟胆固醇（25-OH-C），同时存在或不存在 H2O2。结果表明，所有化学物质均刺激大鼠 GCs 释放孕酮（PG），但 H2O2 剂量依赖性地抑制了这种刺激作用。25-OH-C 刺激 PG 释放，而在三氯司坦存在下，H2O2 抑制了 PG 释放。H2O2 减弱了类固醇生成急性调节蛋白（StAR）蛋白的表达，但并未改变 Western blot 中细胞色素 P450 侧链裂解酶（P450scc）的表达。本研究表明，H2O2 通过 cAMP 途径、蛋白激酶 C（PKC）以及细胞内钙、P450scc 和 StAR 蛋白的活性，抑制 GCs 中 PG 的产生。
