Influence of vagal input on cerebral blood flow in monkeys and dogs after experimental cerebral vasospasm.

Cerebral blood flow (CBF) was a response to experimental subarachnoid haemorrhage (SAH) in four monkeys ,and three dogs. Decrease in CBF was observed in the white and gray matter and in the flow measured within the internal carotid artery as the result of SAH. Bilateral vagotomy enhanced CBF in the gray matter and blood flow in the internal carotid artery to values exceeding the control ones. Results suggest the existence of a receptor susceptible to subarachnoid haemorrhage and connected with vagal nuclei.