Sancho-Tello M, Terranova P F
Department of Physiology, Smith Research Center, University of Kansas Medical Center, Kansas City 66103.
Endocrinology. 1991 Mar;128(3):1223-8. doi: 10.1210/endo-128-3-1223.
Tumor necrosis factor alpha (TNF) increased progesterone production in preovulatory rat follicles in vitro. More than 1 h in the presence of TNF was needed to enhance progesterone secretion, which was only seen after 24 h of culture. Neither cAMP nor cGMP levels in media and follicles increased either at short (5-20 min) or long periods (6-24 h) after TNF stimulation. The protein kinase C (PKC) inhibitor, H-7, blocked TNF-stimulated progesterone in a dose-dependent manner (1-300 mM), with 50% inhibition corresponding to 5.2 microM H-7, it also blocked LH-stimulated progesterone production, but higher doses were needed (50% inhibition corresponding to 54.5 microM H-7). However, the cAMP- and cGMP-dependent protein kinase inhibitor, HA1004, did not block TNF stimulated progesterone. The PKC activator, phorbol 12-myristate 13-acetate (PMA), increased progesterone maximally at 32 nM and above. Low doses of PMA in combination with TNF increased progesterone levels above that stimulated by PMA alone; however with the highest does of PMA (320 nM), TNF was unable to increase follicular progesterone secretion. The time course of progesterone stimulation by PMA was similar to that of TNF. H-7 also blocked PMA and PMA + TNF stimulated progesterone accumulation, with a 50% inhibition corresponding to 4.2 and 4.1 microM H-7, respectively. These results indicate that PKC may be a mediator of TNF-stimulated progesterone secretion in preovulatory rat follicles.
肿瘤坏死因子α（TNF）可在体外增加排卵前大鼠卵泡中的孕酮生成。需要在TNF存在下培养超过1小时才能增强孕酮分泌，这仅在培养24小时后才可见。在TNF刺激后的短时间（5 - 20分钟）或长时间（6 - 24小时）内，培养基和卵泡中的cAMP和cGMP水平均未升高。蛋白激酶C（PKC）抑制剂H - 7以剂量依赖性方式（1 - 300 mM）阻断TNF刺激的孕酮分泌，50%抑制对应的H - 7浓度为5.2 microM，它也阻断促黄体生成素（LH）刺激的孕酮生成，但需要更高剂量（50%抑制对应的H - 7浓度为54.5 microM）。然而，cAMP和cGMP依赖性蛋白激酶抑制剂HA1004并未阻断TNF刺激的孕酮分泌。PKC激活剂佛波酯12 - 肉豆蔻酸酯13 - 乙酸酯（PMA）在32 nM及以上时最大程度地增加孕酮。低剂量的PMA与TNF联合使用可使孕酮水平高于单独使用PMA刺激时的水平；然而，使用最高剂量的PMA（320 nM）时，TNF无法增加卵泡孕酮分泌。PMA刺激孕酮分泌的时间进程与TNF相似。H - 7也阻断PMA和PMA + TNF刺激的孕酮积累，50%抑制对应的H - 7浓度分别为4.2和4.1 microM。这些结果表明PKC可能是TNF刺激排卵前大鼠卵泡中孕酮分泌的介质。
