Interaction between beta-adrenoceptor agonists and alpha 1-adrenergic system. A behavioral study with the clonidine-induced aggression test.

The effects of beta-adrenoceptor agonists on the clonidine-induced aggression in mice were studied. Clenbuterol (0.05-2 mg/kg ip), salbutamol (5-20 mg/kg ip) and terbutaline (10, 20 mg/kg ip) significantly potentiated the effect of clonidine. The enhancement of clonidine aggressiveness induced by clenbuterol (0.5 mg/kg) was prevented by propranolol (2.5, 5 mg/kg) and reduced by prazosin (1 mg/kg). The obtained results provide evidence that stimulation of beta-adrenoceptors facilitates the alpha 1-adrenoceptor-mediated behavior.