Perifusion of rat pituitaries: requirements for optimal GnRH-stimulated LH release.
Perifusion of rat pituitaries: requirements for optimal GnRH-stimulated LH release.
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大鼠垂体灌注：最佳 GnRH 刺激 LH 释放的要求。
DOI：
10.1152/ajpendo.1981.240.5.e504
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Conn,PM
中科院分区：
文献类型：
--
作者：
Stern,JE;Conn,PM
采用大鼠半垂体灌流作为促性腺激素释放激素（GnRH）刺激下促黄体生成激素（LH）释放的体外模型。在GnRH（10（-7）M）连续刺激期间，LH释放被EGTA（GnRH前1小时给药1.5或5 mM）或D-600（甲氧基维拉帕米，1 mM，与GnRH同时给药）抑制。这些结果表明，GnRH刺激的LH释放是一个Ca ~（2+）依赖的过程。抑制LH释放所造成的Ca 2+螯合EGTA逆转时，半垂体返回到培养基中没有EGTA。升高培养基K+（至50 mM，不含GnRH）在第1 h刺激Ca 2+依赖性LH释放。放线菌酮（25 μ g/ml）在第1 h后可抑制GnRH刺激的LH释放60%。二丁酰腺苷3 '，5'-环一磷酸（DBcAMP）不刺激LH释放，尽管这种环核苷酸显示出具有生物活性，并通过其刺激同一组织中催乳素释放的能力判断进入垂体细胞。这些数据表明，最佳LH释放响应GnRH需要细胞外Ca 2+，并取决于蛋白质合成。
Perifusion of rat hemipituitaries was used as an in vitro model for luteinizing hormone (LH) release in response to gonadotropin-releasing hormone (GnRH). LH release during continuous stimulation with GnRH (10(-7) M) was inhibited by EGTA (1.5 or 5 mM given 1 h prior to GnRH) or by D-600 (methoxyverapamil, 1 mM, given concomitantly with GnRH). These findings suggested that GnRH-stimulated LH release was a Ca2+-dependent process. Inhibition of LH release caused by Ca2+ chelation with EGTA was reversed when hemipituitaries were returned to medium without EGTA. Elevation of medium K+ (to 50 mM, without GnRH) stimulated Ca2+-dependent LH release during the 1st h. GnRH-stimulated LH release was 60% inhibited by cycloheximide (25 micrograms/ml) after the 1st h. LH release was not stimulated by dibutyryladenosine 3',5'-cyclic monophosphate (DBcAMP), although this cyclic nucleotide was shown to have biological activity and to enter pituitary cells as judged by its ability to stimulate prolactin release from the same tissue. The data suggest that optimal LH release in response to GnRH requires extracellular Ca2+ and depends on protein synthesis.