Batson J M, Krieg R J, Martha P M, Evans W S
Department of Anatomy, Medical College of Virginia, Richmond 23298.
Endocrinology. 1989 Jan;124(1):444-8. doi: 10.1210/endo-124-1-444.
To determine whether a normal complement of androgen receptors is required to permit full expression of sex-related differences in pituitary GH secretion, we compared the GHRH-stimulated GH secretory responses of continuously perifused anterior pituitary cells from normal male, normal female, and androgen-resistant testicular feminized (Tfm) rats. In each experimental replicate, acutely dispersed pituitary cells were exposed to GHRH (0.03-100 nM) administered as 2.5-min pulses in random order at 30-min intervals. The eluate was collected in 5-min fractions for GH determination by RIA. Basal unstimulated secretion of GH by cells from male rats was greater than that by cells from female (P = 0.007) and Tfm (P = 0.03) rats; basal secretion by the other two groups was similar (P = 0.55). Linear concentration-response relationships between GHRH and GH release were defined for cells from male (P = 0.0002), female (P = 0.0001), and Tfm (P = 0.0002) rats. Overall GHRH-stimulated GH secretion by cells from male rats was greater (P less than 0.0001) than that by cells from female rats. Overall secretion by cells from Tfm rats was less (P less than 0.001) than that by cells from male rats but greater (P less than 0.001) than that by cells from female rats. For all experimental groups, body weight was strongly correlated with both basal (r2 = 0.42; P = 0.001) and GHRH-stimulated (r2 = 0.53; P = 0.0001) GH secretion by the dispersed pituitary cells. These data suggest that a deficiency of androgen receptors results in a diminution of the in vitro GH secretory capability of anterior pituitary cells to a level below that by cells from normal males, but not to the level in normal females. The intermediate position of cells from the Tfm rat may represent a partial masculinization or defeminization within this generally female phenotype.
为了确定是否需要正常数量的雄激素受体来使垂体生长激素（GH）分泌中的性别相关差异得以充分表现，我们比较了正常雄性、正常雌性以及雄激素抵抗型睾丸雌性化（Tfm）大鼠连续灌流的垂体前叶细胞对生长激素释放激素（GHRH）刺激的GH分泌反应。在每个实验重复中，将急性分散的垂体细胞以30分钟的间隔，随机顺序暴露于以2.5分钟脉冲形式给药的GHRH（0.03 - 100 nM）。洗脱液以5分钟的馏分收集，用于通过放射免疫分析（RIA）测定GH。雄性大鼠细胞的基础未刺激GH分泌量大于雌性（P = 0.007）和Tfm（P = 0.03）大鼠细胞的分泌量；其他两组的基础分泌量相似（P = 0.55）。定义了雄性（P = 0.0002）、雌性（P = 0.0001）和Tfm（P = 0.0002）大鼠细胞中GHRH与GH释放之间的线性浓度 - 反应关系。总体而言，雄性大鼠细胞受GHRH刺激的GH分泌量大于雌性大鼠细胞（P < 0.0001）。Tfm大鼠细胞的总体分泌量低于雄性大鼠细胞（P < 0.001），但高于雌性大鼠细胞（P < 0.001）。对于所有实验组，体重与分散的垂体细胞的基础（r2 = 0.42；P = 0.001）和GHRH刺激的（r2 = 0.53；P = 0.0001）GH分泌均密切相关。这些数据表明，雄激素受体缺乏导致垂体前叶细胞的体外GH分泌能力降低至低于正常雄性细胞的水平，但未降至正常雌性细胞的水平。来自Tfm大鼠的细胞的中间位置可能代表在这种总体雌性表型内的部分雄性化或去雌性化。
