HEMODYNAMIC, HORMONAL, AND RENAL EFFECTS OF THE PROSTACYCLIN ANALOG ILOPROST IN CONSCIOUS DOGS WITH AND WITHOUT HEART-FAILURE

To test the efficacy of exogenous prostaglandins for vasodilator therapy in heart failure, we studied the effects of the prostacyclin-derivative iloprost (1.5-150 ng/kg/min) in seven conscious dogs before and after induction of heart failure by right ventricular pacing (250/min, 10 days). In healthy dogs, iloprost (150 ng/kg/min) decreased mean arterial blood pressure (MAP) (-45%) by a decrease in total peripheral resistance (TPR) (-55%), and increased cardiac output (CO) (+ 24%) and heart rate (HR) (+ 20%) with no effect on right atrial and pulmonary arterial pressures (RAP, PAP). Plasma norepinephrine (NE) (+ 47%), renin (+ 351%), and aldosterone (+ 126%) were increased. Urine flow (-70%) and Na excretion (-53%) were decreased. Iloprost (15 ng/kg/min) increased renal blood flow (RBF) (+ 29%), but did not change glomerular filtration rate (GFR). In dogs with heart failure, iloprost decreased arterial BP (-31 %), TPR (-42%) and pulmonary vascular resistance (-28%) and increased CO (+ 29%), with no change in RAP and PAP. Plasma NE (+ 34%), renin (+ 385%), and aldosterone (+146%) were increased. RBF was unchanged, GFR (-24%) and filtration fraction (FF) (-30%) were decreased, as was urine flow (-65%). In experimental heart failure, iloprost is a potent arteriolar dilator, increasing CO with no preload effect. These beneficial effects are limited, however, by further neurohumoral activation and deterioration of renal function. © 1990 Raven Press, Ltd., New York.