Hemodynamic profile of a new cerebral vasodilator, vincamine and of one of its derivatives, apovincaminic acid ethylester (RGH-4405).

The hemodynamic modifications induced by vincamine and by one of its derivatives, apovincaminic acid ethylester (RGH-4405), have been studied in anesthetized and conscious dogs. The two alkaloids induced peripheral vasodilatation in all the experimental models, but their action on systemic blood pressure and heart rate was clearly influenced by anesthesia and was different according to the anesthetic used. In the conscious animals an increase of both heart rate and systemic blood pressure was observed, concomitantly with an increase in femoral and vertebral blood flow and a decrease in renal blood flow. In the renal vascular bed a subsequent decrease in resistance was shown, when all the other measured hemodynamic parameters had returned to control values. The greater increase of vertebral blood flow than of femoral blood flow for the same increment of cardiac output was taken as an indirect demonstration of the selectivity of the two drugs for the cerebral circulation.