Food and water intake suppression by intracerebroventricular administration of substance P in food- and water-deprived rats

The purpose of this present experiment was to determine the effect of substance P (SP) on the feeding and drinking behavior. This was investigated in male rats totally food and water deprived for a period of 24 h. The intracerebroventricular (i.c.v.) administration of SP (20 mu g 10 mu l(-1) rat(-1)) suppressed food and water intakes during the 8 h following administration. At 24 h after i.c.v. injection of SP, the rats were not recovered 10.5% of their feeding and 24.9% of their drinking behavior. However, contrary to what happened with SP, i.c.v. injection of the vehicle of SP did not suppress feeding and drinking behavior, as was observed also in the rats (second control) cannulated i.c.v. but which did not receive any injection. At 48 h after SP injection, no alteration of food and water intakes was observed. These results indicated that SP may function as an endogenous anorexigenic peptide. (C) 1999 Elsevier Science B.V. All rights reserved.