Intracerebroventicular injection of prostaglandin E1 increases γ-aminobutyric acid level in the posterior hypothalamus

The level of gamma-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 PGE1 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). (C) 2000 Elsevier Science Ltd. All rights reserved.