Erythrocyte extracts enhance neurogenic vasoconstriction of dog cerebral arteries in vitro.

Cerebral blood vessels of the dog have been shown to receive vasodilator and constrictor nerves. In isolated ring arterial preparations, neurogenic vasodilation was blocked while neurogenic vasoconstriction was potentiated by hemolysates isolated from hemolyzed erythrocytes. These results suggest that an overall increase in cerebral neurogenic vasoconstriction may occur in vivo following subarachnoid hemorrhage. The significance of this finding in the pathogenesis of cerebral vasospasm is discussed.