INSULIN ENHANCEMENT OF LUTEINIZING-HORMONE AND FOLLICLE-STIMULATING-HORMONE RELEASE BY CULTURED PITUITARY-CELLS
INSULIN ENHANCEMENT OF LUTEINIZING-HORMONE AND FOLLICLE-STIMULATING-HORMONE RELEASE BY CULTURED PITUITARY-CELLS
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DOI：
10.1210/endo-108-4-1441
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发表时间：
1981-01-01
期刊：
影响因子：
4.8
通讯作者：
YEN, SSC
中科院分区：
文献类型：
--
作者：
ADASHI, EY;HSUEH, AJW;YEN, SSC
利用成年去卵巢大鼠垂体前叶细胞的原代培养物，在体外研究了胰岛素在调节基础和促性腺激素释放激素（GnRH）刺激的LH [促黄体生成激素]和FSH [促卵泡激素]释放中的作用。将垂体前叶细胞在存在或不存在胰岛素的情况下在无血清培养基中孵育2天。在胰岛素处理结束时，洗涤细胞并在存在或不存在GnRH的情况下重新孵育，并通过放射免疫测定法测量释放到培养基中的LH和FSH。用胰岛素（1.0 μ g/ml）处理2天导致LH和FSH的基础和最大释放均显著增加，以及GnRH在LH和FSH释放方面的ED 50值分别降低3.2倍和6.3倍。用增加浓度（0.1- 10，000 ng/ml）的胰岛素处理，导致GnRH的剂量依赖性增加（3 × 10 - 4）。10-10 M）刺激LH和FSH的释放。胰岛素的这种作用在1 ng/ml（24 μ U/ml）的生理浓度下是显著的（P < 0.05），ED 50值为4.0ng/ml。增加暴露于胰岛素的持续时间导致GnRH的时间依赖性增加（3 × 10 - 4）。10-10 M）刺激LH释放，在24 h时变得显著，48 h时观察到最大增强。胰岛素的作用是特异性的;表皮或成纤维细胞生长因子不增强LH的释放。胰岛素的增强作用与细胞增殖或蛋白质或LH合成的总体变化无关。胰岛素的作用与环境葡萄糖浓度无关。然而，胰岛素对在补充血清的培养基中培养的促性腺激素细胞没有影响。促性腺激素细胞显然是胰岛素的靶细胞，胰岛素可能直接作用于垂体前叶，调节促性腺激素的释放。
The role of insulin in the regulation of basal and gonadotropin-releasing hormone (GnRH)-stimulated release of LH [luteinizing hormone] and FSH [follicle stimulating hormone] was investigated in vitro using primary cultures of rat anterior pituitary cells from adult ovariectomized rats. Anterior pituitary cells were incubated for 2 days in the presence or absence of insulin in a serum-free medium. At the end of the insulin treatment, the cells were washed and reincubated in the presence or absence of GnRH, and the LH and FSH released into the medium were measured by radioimmunoassay. Treatment with insulin (1.0 .mu.g/ml) for 2 days resulted in significant increases in both the basal and the maximal release of LH and FSH, as well as a 3.2- and 6.3-fold decrease in the ED50 values for GnRH in terms of LH and FSH release, respectively. Treatment with increasing concentrations (0.1-10,000 ng/ml) of insulin, led to a dose-dependent increase in the GnRH (3 .times. 10-10 M)-stimulated release of both LH and FSH. This effect of insulin was significant (P < 0.05) at a physiological concentration of 1 ng/ml (24 .mu.U/ml) with an ED50 value of 4.0 ng/ml. Increasing duration of exposure to insulin resulted in time-dependent increases in the GnRH (3 .times. 10-10 M)-stimulated release of LH, becoming significant at 24 h with maximal enhancement observed by 48 h. The effect of insulin was specific; epidermal or fibroblast growth factor did not enhance LH release. The augmenting effect of insulin was not associated with cellular proliferation or an overall change in protein or LH synthesis. The effect of insulin was independent of the ambient glucose concentration. Insulin was, however, without effect on gonadotrophs cultured in a serum-supplemented medium. The gonadotroph evidently constitutes a target cell of insulin and that insulin may act directly on the anterior pituitary in the regulation of gonadotropin release.