体外促性腺激素释放激素对人催乳素分泌的调节

Regulation of human prolactin secretion by gonadotropin-releasing hormone in vitro.

作者信息

Blackwell R E, Rodgers-Neame N T, Bradley E L, Asch R H

出版信息

Fertil Steril. 1986 Jul;46(1):26-31.

Abstract

The regulation of human prolactin (PRL) secretion by gonadotropin-releasing hormone (GnRH) was evaluated with human pituitary monolayer cell cultures. Synthetic GnRH stimulated PRL secretion when exposed to cells in an estrogen-depleted environment. This response was inhibited by pretreatment of the cells with 17 beta-estradiol (E2). A 10(-5) M GnRH antagonist inhibited luteinizing hormone (LH) but not PRL secretion when cells were maintained in an estrogen-depleted environment. However, the GnRH antagonist inhibited basal PRL secretion when cells were maintained in medium containing 10(-8) M E2. The 10(-5) M GnRH antagonist, when coincubated with 10(-5) M GnRH inhibited the release of PRL in an estrogen-depleted environment. However, coincubation of the 10(-5) M GnRH antagonist with 10(-5) M thyrotropin-releasing hormone (TRH) failed to inhibit PRL secretion. Incubation of 10(-8) M TRH and 10(-8) M GnRH produced a synergistic release of PRL in an estrogen-depleted environment. These observations led us to conclude that GnRH stimulates PRL secretion by direct action on human pituitary cells and that GnRH acts either via the gonadotrope or through receptors on the galactotrope other than that acted upon by TRH to release PRL.

摘要

采用人垂体单层细胞培养法评估促性腺激素释放激素（GnRH）对人催乳素（PRL）分泌的调节作用。在雌激素缺乏的环境中，合成GnRH作用于细胞时可刺激PRL分泌。细胞经17β-雌二醇（E2）预处理后，该反应受到抑制。当细胞维持在雌激素缺乏的环境中时，10⁻⁵ M GnRH拮抗剂可抑制促黄体生成素（LH）分泌，但不抑制PRL分泌。然而，当细胞维持在含有10⁻⁸ M E2的培养基中时，GnRH拮抗剂可抑制基础PRL分泌。在雌激素缺乏的环境中，10⁻⁵ M GnRH拮抗剂与10⁻⁵ M GnRH共同孵育时，可抑制PRL释放。然而，10⁻⁵ M GnRH拮抗剂与10⁻⁵ M促甲状腺激素释放激素（TRH）共同孵育时，未能抑制PRL分泌。在雌激素缺乏的环境中，10⁻⁸ M TRH与10⁻⁸ M GnRH共同孵育可产生协同性PRL释放。这些观察结果使我们得出结论，GnRH通过直接作用于人垂体细胞刺激PRL分泌，并且GnRH通过促性腺激素细胞或通过与TRH作用于释放PRL的受体不同的泌乳激素细胞受体发挥作用。