Evidence for the Involvement of an Energy-Dependent process in Gonadotropin-Releasing Hormone-Stimulated Luteinizing Hormone Release by Rat Anterior Pituitary*

Abstract

The involvement of an energy-dependent process in gonadotropin-releasing hormone-(GnRH) stimulated LH release in the anterior pituitary has been examined. Inhibitors of both glycolysis and oxidative phosphorylation inhibited stimulation by GnRH of LH release in a time- and dose-dependent manner. Iodoacetate and 2-deoxyglucose inhibited GnRH-stimulated LH release, and this inhibition was not overcome by the addition of pyruvate. Similarly carbonyl cyanide m-chlorophenylhydrazine, an uncoupler of oxidative phosphorylation, and sodium azide, an inhibitor of electron transport, decreased ATP levels, enhanced lactate accumulation, and inhibited GnRH-stimulated LH release. These studies demonstrate that inhibition of glycolysis and oxidative phosphorylation with metabolic inhibitors lead to inhibition of GnRH-stimulated LH release. Based on these results, it is postulated that GnRH-stimuoated LH release is dependent on an energy-dependent process.