γ-GABA对大鼠离体培养颗粒细胞生成雌二醇的影响及作用机制

EFFECT OF γ-GABA ON ESTRADIOL PRODUCTION AND ITS MECHANISM BY RAT GRANULOSA CELLS CULTURED IN VITRO

目的和方法 :实验采用离体培养大鼠颗粒细胞的方法 ,观察外源性γ GABA对其雌二醇生成影响。为进一步探讨其作用机制 ,还观察在γ GABA受体激动剂蝇覃醇、蛋白质合成抑制剂放线菌酮、腺苷酸环化酶激动剂forskolin作用下 ,γ GABA对颗粒细胞生成雌二醇的影响。结果 :γ GABA抑制大鼠颗粒细胞的雌二醇生成 ,蝇覃醇有同样作用。γ GABA减少forskolin作用下的大鼠颗粒细胞的雌二醇生成。结论 :γ GABA抑制大鼠颗粒细胞雌二醇的生成 ,可能是通过γ GABA受体的途径 ,且与细胞内腺苷酸环化酶系统有关。

Aim: To evaluate the effect of γ-GABA on estradiol secretion and its mechanism by rat granulosa cells cultured in vitro .Methods: The immature female rats were killed after 48 h pretreated with PMSG.Their ovaries were taken out and granulosa cells were obtained by puncturing the follicles. Granulosa cells were cultured in KRBGAL for 1 h and treated with reagents for a further 2 h. The production of estradiol was assayed by RIA. Results: γ-GABA inhibited estradiol secretion and also inhibited hCG-induced estradiol secretion in cultured rat grallulosa cells. Muscimol (γ-GABA receptor agonist) also inhibited estradiol secretion and γ-GABA decreased forskolininduced estradiol secretion in culturd rat granulosa cells. Conclusion:γ-GABA inhibited estradiol secretion in cultured rat granulosa cells. The effect of γ-GABA may be mediated by γ-GABA receptor and adenylate-cAMP messenger system.