AVP V1b selective antagonist SSR149415 blocks aggressive behaviors in hamsters.

Arginine vasopressin (AVP) has been implicated in a variety of physiological and behavioral responses to stress. Synthesis of receptor-selective AVP agonist and antagonist compounds allows differential analysis of the specific roles of particular receptor subtypes with respect to these responses. Here, effects of the recently synthesized AVP V1b selective antagonist, SSR149415, were examined for offensive aggression in male Syrian hamsters, using a resident-intruder paradigm. Oral administration of vehicle or 1, 10, or 30 mg/kg of SSR149415 to resident hamsters was followed by evaluation of a range of aggression-related measures of residents confronted by intruders. The 10 and 30 mg/kg doses significantly reduced the duration of offensive sideways and chase behaviors, and the 30 mg/kg dose also reduced chase frequency. The 10 and 30 mg/kg dose also significantly reduced frequency and duration of olfactory investigation and duration of flank marking. These findings suggest a link between activity of the V1b receptor and the modulation of offensive aggression. These findings agree with previous research on V1b receptor effects in suggesting that antagonism of this receptor may be useful in modulating a range of emotional responses to highly stressful or threatening conditions.