Nitric oxide reduces body temperature and sympathetic input to brown adipose tissue during PGE 1-hyperthermia

Abstract

The firing rate of the nerves innervating interscapular brown adipose tissue (IBAT) and IBAT and colonic temperatures (T IBAT and T c) were monitored in urethane-anaesthetized male Sprague-Dawley rats. These variables were measured for 40 min before (baseline values) and 40 min after a 4 μmoles l-arginine ( l-arg) or 400 nmoles nitroprusside (NP) injection in a lateral cerebral ventricle and an intracerebroventricular administration of 500 ng prostaglandin E 1 (PGE 1). The same variables were monitored in other rats with l-arg or NP or PGE 1 administration alone. No drug was injected in control rats. The results show that l-arg or NP injection reduces the increases in firing rate, T IBAT, T c induced by PGE 1 These findings suggest that nitric oxide is important in the control of thermogenic changes during the PGE 1 hyperthermia.