The block of central vasopressin V-1 but not V-2 receptors suppresses grooming behavior and hypothermia induced by intracerebroventricular vasopressin in male rats

The role of central vasopressin V-1 receptors in grooming behavior induced by vasopressin and oxytocin was studied in male rats of the Wistar strain. The intracerebroventricular (ICV) injection of vasopressin (3 mu g/5 mu l) induced hypothermia and enhanced novelty-induced grooming 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 stimulating action of vasopressin on novelty-induced grooming and its hypothermic effect. The ICV injection of a selective vasopressin V-2 receptor antagonist failed to affect vasopressin-induced grooming and hypothermic effect. An increase in core temperature was observed in oxytocin-injected animals pretreated with the vasopressin V-1 receptor antagonist. Furthermore, pretreatment with the antagonist did not affect grooming induced by oxytocin. These results suggest that enhancement of grooming behavior and influence on thermoregulation are differently regulated by central receptors for vasopressin and oxytocin. (C) 1997 Elsevier Science Inc.