Serotonin, the Carotid Body, and Cranial Vessels in Migraine

Abstract

IN GENERAL, the infusion of serotonin (5-hydroxytryptamine, 5HT) constricts large arteries and veins but dilates small vessels, although the effect on arterioles depends upon the previous degree of neurogenic vasoconstriction.^1-6 Injection of serotonin into the internal carotid artery of the monkey has been reported as inducing vasoconstriction in the internal carotid circulation,⁷ and direct application of serotonin has been shown to constrict the exposed cerebral blood vessels of the cat and also to produce cortical blanching in some instances.⁸ In contrast to this, Swank and Hissen^" found that flow in the common carotid artery of the dog increased by about 20% in most cases when serotonin was injected into the internal or common carotid arteries. Sicuteri10 reported that the intracarotid injection of serotonin in man increased the amplitude of arterial pulsations recorded during continuous monitoring of cerebrospinal fluid (CSF) pressures, but there is some doubt