Feeding, drinking, and temperature responses of chickens to intracerebroventricular histamine

The present study examines the effects of intracerebroventricular injection s of histamine (HA) and two HA antagonists, the Hi receptor antagonist chlo ropheneramine maleate (CM) and the H-2 receptor antagonist cimetidine (CIM) , on food and water consumption and body temperature in chickens. Single-Co mb White Leghorns (SCWL) and broiler cockerels were utilized for these expe riments. The first pair of experiments consisted of intracerebroventricular injections of RA and its effects on food and water consumption. HA was inf used at dosages of 0, 25, 50, and 100 mug/10 mul of artificial cerebrospina l fluid (aCSF). HA significantly decreased food and water intake in a dose- dependent manner. The second pair of experiments examined the effects of HA on water intake while birds had no access to feed. Water intake was not si gnificantly affected by intracerebroventricular injections of HA. The next pair of experiments examined the effects of HA on body temperature. In SCWL , body temperature was not affected by HA until 165 min postinjection when HA decreased temperature in a quadratic dose-response with maximum hypother mia being achieved at a dose of 25 mug. In contrast, HA increased body temp erature in broilers beginning at 75 min postinjection. In the final series of experiments, the anorexia induced by HA was attenuated in SCWL and broil ers with pretreatment of either CM or CIM. These results suggest that HA ha s an anorexigenic effect in SCWL and broiler cockerels, and this effect is mediated by both Hi and Hz receptors. Water intake is not directly affected by the intracerebroventricular injection of HA. Whereas HA increased body temperature in broilers, the response in SCWL is equivocal. (C) 2001 Elsevi er Science Inc. All rights reserved.