Effects of papaveroline-monosulphate on the systemic and regional circulation in the dog

The effects of papaveroline 6'-sulphonic of N-methylglucamine (UTEN), administered by intravenous injection in doses ranging from 10 to 20 mg/kg, on cardiac dynamics and peripheral blood flow distribution were studied in conscious and anesthetized dogs, using electromagnetic flowmeters implanted around the ascending aorta, pulmonary artery, left coronary artery, superior mesenteric artery, and renal and external iliac arteries. In the conscious dogs, blood pressure after the injection of the drug showed an initial fall and returned to normal control values after a transitory increase. The changes in aortic pressure were accompanied by an increase in heart rate, cardiac output, stroke volume and cardiac work. The administration of UTEN was also associated with an increase in the peripheral blood flow and a decrease in their calculated resistances and in total peripheral resistances. Similar variations were observed in the anesthetized dogs. The effects of UTEN were compared with those of other vasodilator drugs (papaverine, isoxsuprine and D.E.D.). From the results obtained it is possible to conclude that UTEN produces a vasodilation in all investigated vessels, whereas other vasodilator agents only act in some particular vascular beds; moreover, the effect of UTEN is longer-lasting. There is also a probable constriction in the capacitance vessels, as shown by haemodynamic changes in the pulmonary circulation.