Intracerebroventicular injection of prostaglandin E 1 increases γ-aminobutyric acid level in the posterior hypothalamus

Abstract

The level of γ-aminobutyric acid (GABA) in the posterior hypothalamus, the firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), IBAT and colonic temperatures ( T IBAT and T c) were monitored in urethane-anesthetized male Sprague–Dawley rats. These variables were measured before and after an intracerebroventricular injection of 500 ng prostaglandin E 1 (PGE 1). The same variables were monitored in other rats with saline injection. The results showed that PGE 1 caused an increase in GABA concentration, firing rate, T IBAT, T c. These findings suggest that GABA-ergic tone in the posterior hypothalamus is important in the control of the sympathetic and thermogenic changes induced by PGE 1.