Saragüeta P, Krimer A R, Charreau E H, Tesone M
Instituto de Biología y Medicina Experimental, Buenos Aires, Argentina.
J Steroid Biochem. 1989 Mar;32(3):393-7. doi: 10.1016/0022-4731(89)90212-4.
The effect of insulin on the function of rat luteal cells in monolayer culture was examined. Cells were obtained from PMSG-hCG primed immature rats and further cultured in serum free medium with or without insulin. The hormone produced an increase of progesterone production and maximal stimulation was achieved at 0.2 nM of insulin (100% stimulation). This effect was enhanced by addition of methyl-isobutyl-xantine (MIX 0.1 mM) to the culture medium. However, the stimulation produced by LH was not augmented by the presence of insulin. The conversion of progesterone into 20 alpha-hydroxy-progesterone was also enhanced after insulin treatment. Luteal cells were also cultured in the presence of 25-hydroxy-cholesterol (10 micrograms/ml). In these conditions insulin produced a 2-fold increase in progesterone production. Aromatase activity was assessed by adding androstenedione (0.25 microM) as substrate. Insulin produced a 14-fold stimulation of estradiol production after 24 h of culture. Insulin action was tested in short time incubations of luteal cells in a glucose free medium, in these experiments the hormone was able to induce a significant increase in progesterone and 20 alpha-hydroxy-progesterone production. These data suggest that luteal cell function is regulated by insulin and that this hormone has a direct effect on the steroidogenic process.
研究了胰岛素对单层培养的大鼠黄体细胞功能的影响。细胞取自经孕马血清促性腺激素（PMSG）-人绒毛膜促性腺激素（hCG）预处理的未成熟大鼠，并在添加或不添加胰岛素的无血清培养基中进一步培养。该激素可使孕酮分泌增加，在胰岛素浓度为0.2 nM时达到最大刺激效果（100%刺激）。向培养基中添加甲基异丁基黄嘌呤（MIX 0.1 mM）可增强这种作用。然而，胰岛素的存在并未增强促黄体生成素（LH）所产生的刺激作用。胰岛素处理后，孕酮向20α-羟孕酮的转化也增强。黄体细胞也在25-羟基胆固醇（10微克/毫升）存在的情况下进行培养。在这些条件下，胰岛素使孕酮分泌增加了2倍。通过添加雄烯二酮（0.25 microM）作为底物来评估芳香化酶活性。培养24小时后，胰岛素使雌二醇分泌增加了14倍。在无葡萄糖培养基中对黄体细胞进行短时间孵育以测试胰岛素的作用，在这些实验中，该激素能够显著增加孕酮和20α-羟孕酮的分泌。这些数据表明，黄体细胞功能受胰岛素调节，且该激素对类固醇生成过程有直接影响。
