Cerebral Arterial Spasm

Spasm of the basilar artery in the dog was induced by the injection of blood into the cisterna magna, and documented by means of vertebral angiography. Reserpine was administered to dogs to inhibit the concentration of catecholamines and serotonin in platelets. It was found that constriction of the basilar artery did not occur when the blood injected into the subrachnoid space was taken from dogs that received reserpine, but did occur when untreated blood was used. It was concluded that serotonin is one of the principal agents in the production of spasm of the basilar artery following subarachnoid hemorrhage.