Differences in brain and liver blood flow during and after acute blood loss in rats with different resistance to circulatory hypoxia

Abstract

Variations of blood flow and vascular resistance in the common carotid arteries and of blood flow in the hepatic artery and portal vein are examined during and after acute massive blood loss in rats with low and high resistance to circulatory hypoxia. In rats with low resistance, arterial pressure and the rates of cerebral and hepatic blood macro-and microflow, which have decreased during blood loss, continued to fall during the posthemorrhagic period. After cessation of bleeding, a transient arterial pressure rise to 70 mm Hg is observed in rats with high resistance, while the blood flow via carotid arteries increases to 65% of its initial value, being maintained at this level throughout the period of changes in carotid vascular resistance; intrinsic hepatic arterial blood flow increases to 115% of baseline value, while the portal vein blood flow and hepatic microflow increase to 75%.