LIPID HYDROPEROXIDES EVOKE ANTIGONADOTROPIC AND ANTISTEROIDOGENIC ACTIVITY IN RAT LUTEAL CELLS
LIPID HYDROPEROXIDES EVOKE ANTIGONADOTROPIC AND ANTISTEROIDOGENIC ACTIVITY IN RAT LUTEAL CELLS
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DOI：
10.1210/en.135.6.2723
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发表时间：
1994-12-01
期刊：
影响因子：
4.8
通讯作者：
BEHRMAN, HR
中科院分区：
文献类型：
--
作者：
KODAMAN, PH;ATEN, RF;BEHRMAN, HR
在功能性黄体溶解时，大鼠黄体产生过氧化氢(H_2O_2)，众所周知，它能迅速抑制黄体细胞中对促性腺激素敏感的cAMP和孕酮的产生。随着功能性黄体溶解的开始，大鼠黄体中的过氧化脂质也显著增加，而过氧化氢是脂质过氧化的有效诱导剂。然而，过氧化脂质对细胞功能的作用尚不清楚。本研究的目的是探讨典型的过氧化脂质--过氧化异丙苯(CuOOH)和15(S)-羟基过氧二十碳四烯酸对大鼠黄体细胞的影响。CuOOH对黄体生成素敏感的cAMP积聚(ED(50)，25 mU M)和孕酮的产生(ED(50，20 mU M))均有抑制作用。15(S)-羟基过氧二十碳四烯酸也剂量依赖性地抑制类固醇的生成。用CuOOH处理5分钟内，黄体生成素明显减少，而cAMP的积累直到60分钟才明显受到抑制。8-溴-cAMP和22-羟基胆固醇分别部分逆转和完全逆转CuOOH抑制的孕酮分泌。用邻菲罗啉预先孵育细胞，可完全逆转CuOOH对cAMP积累的抑制作用，并部分逆转其对孕酮生成的影响。放射性标记氨基酸在黄体蛋白中的掺入在2分钟内被CuOOH(25 MU M)显著抑制，60分钟后降至对照水平的40+/-14%。CuOOH(25mU/M)在30min内最大限度地刺激PGE(2)的产生(为对照的180+/-30%)，这一反应可被磷脂酶-AA抑制剂马兜铃酸(100mU/M)和前列腺素(PG)合成抑制剂吲哚美辛(1mU/ml)完全阻断。目前的结果表明，脂质过氧化对促黄体生成素的急性抑制作用发生在cAMP合成的下游，这可能是由于胆固醇用于类固醇合成的损害，可能是通过抑制蛋白质的合成。CuOOH对PGE(2)产生的刺激似乎涉及磷脂酶-az的激活，这是PG合成中的一个限速步骤。过氧化脂质和过氧化氢可能是功能性黄体溶解的中介物。
At functional luteolysis, the rat corpus luteum generates hydrogen peroxide (H2O2), which is known to rapidly inhibit gonadotropin-sensitive cAMP and progesterone production in isolated luteal cells. Lipid peroxides also increase markedly in the rat corpus luteum with the onset of functional luteolysis, and H2O2 is a potent inducer of lipid peroxidation. However, the actions of lipid peroxides on cell function are unknown. The objective of this study was to investigate the impact of typical lipid peroxides, cumene hydroperoxide (CuOOH) and 15(S)-hydroperoxyeicosatetraenoic acid, on rat luteal cells. CuOOH inhibited both LH-sensitive cAMP accumulation (ED(50), 25 mu M) and progesterone production (ED(50), 20 mu M). 15(S)-hydroperoxyeicosatetraenoic acid also dose dependently inhibited steroidogenesis. A significant reduction of LH-stimulated progesterone production was evident within 5 min of treatment with CuOOH, whereas inhibition of cAMP accumulation was not evident until 60 min. 8-Bromo-cAMP and 22-hydroxycholesterol caused partial and complete reversal of CuOOH-inhibited progesterone secretion, respectively. Preincubation of cells with o-phenanthroline completely reversed the inhibitory effect of CuOOH on cAMP accumulation and partially reversed its effect on progesterone production. Incorporation of radiolabeled amino acids into luteal proteins was significantly inhibited by CuOOH (25 mu M) within 2 min of treatment and was reduced to 40 +/- 14% of control levels at 60 min. CuOOH (25 mu M) maximally stimulated PGE(2) production within 30 min of treatment (180 +/- 30% of control), a response that was completely blocked by aristolochic acid (100 mu M), a phospholipase-Aa inhibitor, and indomethacin (1 mu g/ml), a prostaglandin (PG) synthesis inhibitor. The present results suggest that the acute inhibitory action of lipid peroxides on LH-stimulated progesterone production occurs down-stream of cAMP synthesis and appears to be due to impaired cholesterol utilization for steroidogenesis, possibly through inhibition of protein synthesis. The stimulation of PGE(2) production by CuOOH appears to involve the activation of phospholipase-az, which is a rate-limiting step in PG synthesis. Lipid peroxides as well as H2O2 may serve as mediators of functional luteolysis.