Kitahara S, Kotsuji F, Keeping H S, Oshima H, Troen P, Winters S J
Department of Medicine, Montefiore Hospital, Pittsburgh, Pennsylvania 15213.
Endocrinology. 1991 Feb;128(2):710-6. doi: 10.1210/endo-128-2-710.
There is accumulating evidence that the differential regulation of LH and FSH secretion in the male is partly accomplished by the direct actions of testosterone (T) and inhibin on the pituitary. The present study was designed to examine the interaction between T and inhibin, in the presence and absence of GnRH, using dispersed pituitary cells in monolayer culture and cells perifused with pulses of GnRH from intact, 2-week castrated, and castrated T-replaced young adult male rats. The effect of partially purified inhibin from primate Sertoli cell culture medium (pSCI) to suppress basal FSH secretion was similar with pituitary cells from intact and castrated rats. T increased basal FSH secretion in the presence or absence of pSCI but did not alter the dose-dependent suppression of FSH by pSCI with cells from either intact or castrate rats. Castration increased basal FSH and LH secretion, whereas only basal FSH release was increased with cells from T-replaced castrates. T pretreatment increased the action of pSCI to suppress GnRH-stimulated FSH and LH release from perifused pituitary cells. These data indicate that T and inhibin exert opposite but independent effects on basal FSH release. The action of inhibin to suppress basal FSH secretion is not impaired by the absence of T and inhibin subsequent to castration. By contrast, the actions of T and inhibin to suppress GnRH-stimulated gonadotropin secretion are coordinated and interrelated.
越来越多的证据表明，雄性体内促黄体生成素（LH）和促卵泡生成素（FSH）分泌的差异调节部分是由睾酮（T）和抑制素对垂体的直接作用完成的。本研究旨在利用单层培养的分散垂体细胞以及用来自完整、2周去势和去势后用T替代的成年雄性大鼠的GnRH脉冲进行灌流的细胞，研究在有和没有GnRH的情况下T与抑制素之间的相互作用。从灵长类支持细胞培养基中部分纯化的抑制素（pSCI）抑制基础FSH分泌的作用，在完整大鼠和去势大鼠的垂体细胞中相似。无论有无pSCI，T均可增加基础FSH分泌，但不改变pSCI对完整或去势大鼠细胞FSH的剂量依赖性抑制作用。去势增加基础FSH和LH分泌，而在去势后用T替代的大鼠的细胞中，仅基础FSH释放增加。T预处理增强了pSCI抑制GnRH刺激的灌流垂体细胞释放FSH和LH的作用。这些数据表明，T和抑制素对基础FSH释放发挥相反但独立的作用。去势后T和抑制素的缺失并不损害抑制素抑制基础FSH分泌的作用。相比之下，T和抑制素抑制GnRH刺激的促性腺激素分泌的作用是协同且相互关联的。
