Ohtsuka S, Nishizaki T, Tasaka K, Miyake A, Tanizawa O, Yamatodani A, Wada H
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
Acta Endocrinol (Copenh). 1989 May;120(5):644-8. doi: 10.1530/acta.0.1200644.
Estradiol is known to stimulate gonadotropin-releasing hormone release from the rat medio-basal hypothalamus. Studies were made in an in vitro perifusion system on whether catecholamine and/or histamine was involved in estradiol-induced GnRH release. Normal cycling female rats were decapitated in diestrus II and their medio-basal hypothalami were combined and, perifused with Earl's balanced salt solution containing 0.01% bovine serum albumin bubbled with 95% O2 and 5% CO2. The levels of norepinephrine, dopamine, and histamine and of GnRH in the effluent were measured by HPLC and radioimmunoassay, respectively. Administration of 10(-6) mol/l estradiol resulted in releases of norepinephrine, dopamine, histamine and GnRH at levels of 98, 70, 91 and 288%, respectively, of initial values. Administration of 10(-6) mol/l norepinephrine or dopamine resulted in no increase in histamine release, and administration of 10(-6) mol/l histamine did not increase release of norepinephrine or dopamine. These data suggest that estradiol stimulates the releases of GnRH, catecholamine and histamine from the rat medio-basal hypothalamus, and that it increases GnRH release independently through catecholamine and histamine. As we found previously that norepinephrine or histamine stimulates GnRH release from the medio-basal hypothalamus, we conclude that estradiol stimulates releases of norepinephrine and histamine, resulting in GnRH release from the medio-basal hypothalamus.
已知雌二醇可刺激大鼠中基底下丘脑释放促性腺激素释放激素。我们利用体外灌流系统研究了儿茶酚胺和/或组胺是否参与雌二醇诱导的促性腺激素释放激素释放。在动情周期Ⅱ的正常成年雌性大鼠断头处死，取其下丘脑基底部进行合并，用含0.01%牛血清白蛋白的Earle平衡盐溶液灌流，通以95%氧气和5%二氧化碳混合气体。分别采用高效液相色谱法和放射免疫分析法测定灌流液中去甲肾上腺素、多巴胺、组胺以及促性腺激素释放激素的水平。给予10(-6)mol/L雌二醇后，去甲肾上腺素、多巴胺、组胺和促性腺激素释放激素的释放量分别为初始值的98%、70%、91%和288%。给予10(-6)mol/L去甲肾上腺素或多巴胺后，组胺释放量未增加，给予10(-6)mol/L组胺后，去甲肾上腺素或多巴胺的释放量也未增加。这些数据表明，雌二醇可刺激大鼠中基底下丘脑释放促性腺激素释放激素、儿茶酚胺和组胺，且其通过儿茶酚胺和组胺独立增加促性腺激素释放激素的释放。正如我们之前发现去甲肾上腺素或组胺可刺激中基底下丘脑释放促性腺激素释放激素，我们得出结论，雌二醇刺激去甲肾上腺素和组胺的释放，从而导致中基底下丘脑释放促性腺激素释放激素。
