Quetiapine lowers sympathetic and hyperthermic reactions due to cerebral injection of orexin A. Neuropeptides

Since no experiment regarding a possible relation between quetiapine and orexin A has been reported in international literature, this experiment tested the eVect of quetiapine on the sympathetic and thermogenic eVects induced by orexin A. The Wring rates of the sympathetic nerves to interscapular brown adipose tissue (IBAT), along with IBAT, colonic temperatures and heart rate were monitored in urethane-anesthetized male Sprague-Dawley rats before an injection of orexin A (1.5nmol) into the lateral cerebral ventricle and over a period of 150min after the injection. The same variables were monitored in rats with an intraperitoneal administration of quetiapine (5 or 10 mg/kg bw), injected 30 min before the orexin administration. The results show that orexin A increases the sympathetic Wring rate, IBAT, colonic temperatures and heart rate. This increase is delayed or reduced by the injection of quetiapine. These Wndings indicate that quetiapine aVects the complex reactions related to activation of orexinergic system. Possible inXuences on the control of body weight and temperature are discussed.