肾上腺素、去甲肾上腺素和多巴胺对促性腺激素释放激素诱导的黄体生成素体外分泌的影响。

Effects of epinephrine, norepinephrine, and dopamine on gonadotropin-releasing hormone-induced secretion of luteinizing hormone in vitro.

作者信息

Swartz S R, Moberg G P

出版信息

Endocrinology. 1986 Jun;118(6):2425-31. doi: 10.1210/endo-118-6-2425.

Abstract

Recent evidence indicates that catecholamines may directly alter anterior pituitary function. In the present study, an in vitro perifusion system was used to investigate whether catecholamines affect the gonadotrope. Pituitary tissue from castrated ram lambs was incubated in the presence of epinephrine (EPI), norepinephrine (NE), or dopamine (DA). During a 2-h treatment period, neither DA (10(-8) M), NE (10(-7) M), nor EPI (10(-7) - 10(-9) M) significantly affected basal LH secretion. In contrast, the LH response to a subsequent 10(-10) M GnRH challenge was significantly potentiated by NE and EPI. NE increased the amount of LH secreted in response to GnRH 14 +/- 1.1% (P less than 0.01). Likewise, 10(-7), 10(-8), and 10(-9) M EPI resulted in 22 +/- 1.4% (P less than 0.001), 13 +/- 1.2% (P less than 0.001), and 6 +/- 1.3% (P less than 0.03) increases, respectively. The stimulatory effect of 10(-7) M EPI was blocked by pretreatment with propranolol (a beta-adrenergic blocker), but not with phentolamine (an alpha-adrenergic blocker). The beta-adrenergic agonist isoproterenol enhanced GnRH-induced LH secretion 46 +/- 1.5% (P less than 0.001), but had no effect on basal LH release. DA had no effect on LH secretion; however, it inhibited PRL release 24 +/- 0.9% (P less than 0.001). Neither NE, EPI, nor isoproterenol had any effect on PRL secretion. These results suggest that EPI, acting by a beta 2-adrenergic receptor, modulates the pituitary gonadotrope's response to GnRH.

摘要

最近的证据表明，儿茶酚胺可能直接改变垂体前叶功能。在本研究中，使用体外灌流系统来研究儿茶酚胺是否影响促性腺激素细胞。将去势公羊羔的垂体组织在肾上腺素（EPI）、去甲肾上腺素（NE）或多巴胺（DA）存在的情况下进行孵育。在2小时的处理期内，DA（10⁻⁸ M）、NE（10⁻⁷ M）或EPI（10⁻⁷ - 10⁻⁹ M）均未显著影响基础促黄体生成素（LH）分泌。相比之下，NE和EPI显著增强了随后对10⁻¹⁰ M促性腺激素释放激素（GnRH）刺激的LH反应。NE使GnRH刺激下分泌的LH量增加了14±1.1%（P<0.01）。同样，10⁻⁷ M、10⁻⁸ M和10⁻⁹ M的EPI分别使LH分泌增加了22±1.4%（P<0.001）、13±1.2%（P<0.001）和6±1.3%（P<0.03）。10⁻⁷ M EPI的刺激作用可被普萘洛尔（一种β肾上腺素能阻滞剂）预处理阻断，但不能被酚妥拉明（一种α肾上腺素能阻滞剂）阻断。β肾上腺素能激动剂异丙肾上腺素使GnRH诱导的LH分泌增加了46±1.5%（P<0.001），但对基础LH释放无影响。DA对LH分泌无影响；然而，它抑制催乳素（PRL）释放24±0.9%（P<0.001）。NE、EPI和异丙肾上腺素对PRL分泌均无影响。这些结果表明，EPI通过β₂肾上腺素能受体发挥作用，调节垂体促性腺激素细胞对GnRH的反应。