 Increasing dosages of carpaine from 0.5 mg/kg to 2.0 mg/kg resulted in progressive decrease in systolic, diastolic, and mean arterial blood pressure.Selective autonomic nervous blockade with atropine sulfate (1 mg/kg) or propranolol hydrochloride (8 mg/kg) did not alter the circulatory response to carpaine.Carpaine, 2 mg/kg, reduced cardiac output, stroke volume, stroke work, and cardiac power, but the calculated total peripheral resistance remained unchanged.