Effects of hydralazine on liver blood flow in normovolemic dogs

The effects on liver blood flow caused by hydralazine were studied in 14 dogs. Hepatic artery and femoral artery blood flow were estimated with an electromagnetic flow meter. Total hepatic blood flow (THBF) was measured by 133Xenon clearance. Cardiac output (CO) was determined by intravenous injection of Cardio-Green. After 0.2 mg/kg of hydralazine total hepatic blood flow increased by 57%. The hepatic artery blood flow increased by 82% and portal blood flow by 58%. Cardiac output increased by about 50%, while total peripheral vascular resistance decreased. The results further suggest that hydralazine increases portal blood flow. Also the ratio THBF : CO increased. These findings together indicate a hydralazine-induced redistribution of cardiac output with a relatively increased proportion provided to the liver.