Effects of GnRH and drugs that affect cAMP levels on LH synthesis and release.
Effects of GnRH and drugs that affect cAMP levels on LH synthesis and release.
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DOI：
10.1152/ajpendo.1981.241.1.e14
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发表时间：
1981-07
期刊：
影响因子：
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通讯作者：
T. C. Liu;P. S. Wang;G. L. Jackson
中科院分区：
文献类型：
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作者：
T. C. Liu;P. S. Wang;G. L. Jackson
我们研究了基础和促性腺激素释放激素（GnRH）刺激的促黄体生成激素（LH）释放和合成对提高细胞内腺苷3 '，5'-环磷酸（cAMP）水平的药物的反应。在GnRH和[3 H]葡萄糖胺存在下，将卵巢切除大鼠的前垂体与药物或不与药物孵育。单独使用时，8-溴-cAMP（8-Br-cAMP）（10 mM）、霍乱毒素（10 μ g/ml）和磷酸二酯酶抑制剂[茶碱，2和8 mM; 3-异丁基-1-甲基黄嘌呤（MIX），0.2 mM]对免疫反应性LH（IR-LH）的释放均无任何可检测的影响。而8-Br-cAMP及其抑制剂则增强GnRH诱导的IR-LH释放（P <0.01）。促性腺激素释放激素（GnRH）、8-Br-cAMP（霍乱毒素）均能升高系统中的总LH（P <0.01），但8 mM茶碱可降低系统中的总LH（P <0.01），而MIX或2 mM茶碱则不影响系统中的总LH。8-Br-cAMP不改变GnRH对整个系统中放射性标记LH的作用，而MIX和2 mM茶碱降低了GnRH对LH的作用。结果提示：1）cAMP不直接影响LH的释放，但可能与GnRH相互作用而增强LH的释放; 2）GnRH和cAMP对LH糖基化的作用方式相似，和3）磷酸二酯酶抑制剂具有干扰LH糖基化的额外作用。
We examined basal and gonadotropin-releasing hormone (GnRH)-stimulated luteinizing hormone (LH) release and synthesis in response to drugs that raise intracellular adenosine 3',5'-cyclic monophosphate (cAMP) levels. Anterior pituitaries from ovariectomized rats were incubated with or without drugs in the presence of GnRH and [3H]glucosamine. Neither 8-bromo-cAMP (8-Br-cAMP) (10 mM), cholera toxin (10 micrograms/ml), nor phosphodiesterase inhibitors [theophylline, 2 and 8 mM; 3-isobutyl-1-methylxanthine (MIX), 0.2 mM] had any detectable effect on release of immunoreactive LH (IR-LH) when used alone. However, 8-Br-cAMP and the inhibitors potentiated (P less than 0.01) GnRH-induced release of IR-LH. Total radiolabeled LH in the system was elevated (P less than 0.01) by either GnRH, 8-Br-cAMP for cholera toxin, but reduced (P less than 0.01) by 8 mM theophylline and unaffected by MIX or 2 mM theophylline. 8-Br-cAMP did not alter the effect of GnRH on radiolabeled LH in the total system, whereas MIX and 2 mM theophylline reduced (P less than 0.05) it. These results suggest that 1) cAMP does not effect LH release directly, but may interact with GnRH to potentiate it, 2) GnRH and cAMP have a similar mode of action on LH glycosylation, and 3) phosphodiesterase inhibitors have additional actions that interfere with LH glycosylation.