Systemic and Renal Hemodynamic Effects of Dopamine and Prostaglandin A alone and in Combination

Abstract

Prostaglandin A (PGA) compounds infused intravenously at rates of 0.125, 0.25 and 0.50 µg/kg/min decreased mean aortic pressure and renal vascular resistance, but did not increase renal blood flow in pentobarbital-anesthetized dogs. In contrast, dopamine increased renal blood flow at infusion rates of 2.5, 5.0 and 7.5 µg/kg/min and increased mean aortic pressure at infusion rates of 5.0 and 7.5 µg/kg/min. With simultaneous infusions of PGA (0.125 and 0.25 µg/kg/min) and dopamine (2.5, 5.0 and 7.5 µg/kg/min), mean aortic pressure decreased and renal blood flow increased. In open-chest dogs, cardiac contractile force was increased more by dopamine than by PGA. Neither agent alone altered heart rate, but when administered together, heart rate increased. PGA (0.01–0.02 µg/kg/min) abolished the increase in blood pressure produced by larger doses of dopamine (15–20 µg/kg/min) without reducing the increase in renal blood flow. Thus, by varying infusion rates of dopamine and PGA, renal blood flow may be increased with no change, an increase or a decrease in arterial pressure.