Inhibition of Serotonin Synthesis by Para-Chlorophenylalanine in Patients with the Carcinoid Syndrome

Abstract

ALTHOUGH the role of 5-hydroxytryptamine (serotonin, 5HT) in the pathophysiology of the carcinoid syndrome, and especially in flush production, has been seriously questioned,² the fact remains that increased production of serotonin is a hallmark of the condition. If it were possible effectively to inhibit the formation of this pharmacologically potent amine in patients with carcinoid tumors, a likely result would be a better understanding of the clinical significance of serotonin. A possibility of achieving this goal appeared with the studies of Koe and Weissman³ showing that para-chlorophenylalanine (PCP) is a potent and selective depletor of tissue serotonin in animals. It . . .