THE BLOCK OF CENTRAL VASOPRESSIN V-1 BUT NOT V-2 RECEPTORS SUPPRESSESGROOMING BEHAVIOR AND HYPOTHERMIA INDUCED BY INTRACEREBROVENTRICULAR VASOPRESSIN IN MALE RATS

The role of central vasopressin V-1 receptors in grooming behavior ind uced by vasopressin and oxytocin was studied in male rats of the Wista r strain. The intracerebroventricular (ICV) injection of vasopressin ( 3 mu g/5 mu l) induced hypothermia and enhanced novelty-induced groomi ng behavior. Enhanced grooming but not hypothermia was also induced by ICV injection of oxytocin (3 mu g/5 mu l). The central administration of a selective vasopressin V-1 receptor antagonist prevented the stim ulating action of vasopressin on novelty-induced grooming and its hypo thermic effect. The ICV injection of a selective vasopressin V-2 recep tor antagonist failed to affect vasopressin-induced grooming and hypot hermic effect. An increase in core temperature was observed in oxytoci n-injected animals pretreated with the vasopressin V-1 receptor antago nist. Furthermore, pretreatment with the antagonist did not affect gro oming induced by oxytocin. These results suggest that enhancement of g rooming behavior and influence on thermoregulation are differently reg ulated by central receptors for vasopressin and oxytocin. (C) 1997 Els evier Science Inc.