Divergent Effects of Serotonin on Coronary-Artery Dimensions and Blood Flow in Patients with Coronary Atherosclerosis and Control Patients

IT has been suggested that selected platelet-derived substances, such as serotonin (5-hydroxytryptamine) and thromboxane A 2 , may play an important part in the pathophysiology of certain acute coronary artery disease syndromes. 1 , 2 Specifically, increased concentrations of serotonin have been found in blood samples collected from the coronary sinus of patients with complex coronary-artery lesions. 3 Similarly, plasma from the coronary sinus of patients with severe coronary artery disease contains a humoral factor capable of constricting canine coronary arteries in vitro. 4 This vasoconstriction is prevented by serotonin-receptor antagonists. 4 In an experimental model of coronary-artery stenosis and endothelial injury, which is thought to . . .