Tse A, Hille B
Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle 98195.
Science. 1992 Jan 24;255(5043):462-4. doi: 10.1126/science.1734523.
Secretion of gonadotropic hormones from pituitary gonadotropes in response to gonadotropin-releasing hormone (GnRH) is essential for regulation of reproductive potential. Gonadotropes from male rats exhibited an unusual form of cellular excitation that resulted from periodic membrane hyperpolarization. GnRH induced an oscillatory release of intracellular Ca2+ via a guanosine triphosphate (GTP) binding protein-coupled phosphoinositide pathway and hyperpolarized the gonadotrope periodically by opening apamin-sensitive Ca(2+)-activated K+ (SK) channels. Each hyperpolarization was terminated by firing of a few action potentials that may result from removal of inactivation from voltage-gated Na+ and Ca2+ channels.
垂体促性腺细胞分泌促性腺激素以响应促性腺激素释放激素（GnRH）对于调节生殖潜能至关重要。雄性大鼠的促性腺细胞表现出一种不寻常的细胞兴奋形式，这种兴奋形式源于周期性的膜超极化。GnRH通过鸟苷三磷酸（GTP）结合蛋白偶联的磷酸肌醇途径诱导细胞内Ca2+的振荡释放，并通过打开蜂毒明肽敏感的Ca(2+)激活K+（SK）通道使促性腺细胞周期性超极化。每次超极化通过激发一些动作电位而终止，这些动作电位可能是由于电压门控Na+和Ca2+通道失活的去除所致。
