[Pathological and compensatory processes in the cerebral circulation during blood transfusion shock]

In experiments on dogs the intravenous injection of heterogenous blood resulted in a decrease of total arterial pressure, weakening of the brain blood flow, fall of Po2 and pH in the brain cortex. A simultaneous constriction if inner carotid arteries is depending on direct action on the vascular wall of heterogenous proteins and on a release in it of physiologically active substances, such as serotonin. Fine pial arteries were dilated by the compensatory mechanism that was not associated with a decrease of intravascular and with direct action of hypoxia or acid metabolites on vascular walls. It was proposed that the trigger mechanism of this vasodilatation is hypoxic changes of metabolism in the nervous tissue.