A Comparative Study of the Action of Octaverine, Perparine and Papaverine on the Circulatory and Respiratory Systems

Abstract

Summary A comparative study has been made of the activities of papaverine and two synthetic analogues—octaverine and perparine—on the circulatory and respiratory systems in rabbits. Octaverine and perparine possess a hypotensive activity approximately twice as great as that of papaverine. The depressor action of octaverine is of longer duration than that of the other two alkaloids and there is no secondary rise in blood pressure above the normal level. Papaverine causes a slight decrease, while octaverine and perparine effect a substantial increase, in the ventilation rate as measured by the product of respiratory rate and amplitude. Octaverine and perparine are twice to three times as active as papaverine in counteracting adrenaline induced hypertension. Octaverine has a higher adrenolytic activity than the other two compounds as shown by the rise in threshold toxicity of adrenaline in mice. 5 Perparine is slightly less active, while octaverine is slightly more active, than papaverine in increasing the coronary flow in the perfused isolated heart.