Evidence for cAMP as a mediator of gonadotropin secretion from female pituitaries.
Evidence for cAMP as a mediator of gonadotropin secretion from female pituitaries.
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DOI：
10.1152/ajpendo.1987.253.3.e290
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发表时间：
1987-09
期刊：
影响因子：
--
通讯作者：
G. A. Bourne;D. M. Baldwin
中科院分区：
文献类型：
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作者：
G. A. Bourne;D. M. Baldwin
氟芬那酸钠可抑制促性腺激素释放激素（GnRH）刺激的环磷酸腺苷（cAMP）增加，用于评价cAMP作为GnRH刺激的促性腺激素分泌介质的潜在作用。四分之一的垂体从diestrous II雌性大鼠灌注在37摄氏度，和连续的流出物馏分收集每10分钟。GnRH的管理导致在一个特征性的双相反应促黄体生成素（LH）和促卵泡激素（FSH），而5 μ M放线菌酮抑制二次增强反应（第二阶段）的两种激素。输注0.1 mM氟芬那酯以类似于放线菌酮的方式抑制GnRH刺激的促性腺激素分泌，而5 mM二丁酰cAMP与GnRH和氟芬那酯联合给药导致LH和FSH分泌恢复。二丁酰cAMP恢复的反应似乎是蛋白质合成依赖性的和特异性的cAMP。这些结果表明，虽然环核苷酸不参与LH和FSH的急性释放，但它似乎在激素的II期释放中发挥关键但间接的作用，通过刺激从头蛋白质合成。
Sodium flufenamate, which inhibited gonadotropin-releasing hormone (GnRH)-stimulated increases in adenosine 3',5'-cyclic monophosphate (cAMP), was used to evaluate the potential role of cAMP as a mediator of GnRH-stimulated gonadotropin secretion. Quartered pituitaries from diestrous II female rats were perifused at 37 degrees C, and sequential effluent fractions were collected every 10 min. Administration of GnRH resulted in a characteristic biphasic response for both luteinizing hormone (LH) and follicle-stimulating hormone (FSH), whereas 5 microM cycloheximide inhibited the secondary augmented responses (phase II) of both hormones. Infusions of 0.1 mM flufenamate inhibited GnRH-stimulated gonadotropin secretion in a manner similar to that of cycloheximide, whereas the administration of 5 mM dibutyryl cAMP in combination with GnRH and flufenamate resulted in the restoration of LH and FSH secretion. The dibutyryl cAMP-restored response appeared to be protein synthesis dependent and specific for cAMP. These results suggest that although the cyclic nucleotide is not involved in the acute release of LH and FSH, it does appear to play a pivotal but indirect role in phase II release of the hormones, by effects involving the stimulation of de novo protein synthesis.