Serotonin (5-Hydroxytryptamine); the Last Four Years

Abstract

Serotonin participates in a wide variety of metabolic and physiologic functions. The author''s discussion, based on 529 references, includes these topics identification and determination of serotonin; its sources and manner of release (brain, blood, mast cells, gastrointestinal tract); its metabolism and the determination of its metabolic products in urine; its antagonists; actions upon blood pressure, cardiac output, heart, pulmonary circulation, chemoceptors, renal circulation, special vascular areas, cardiovascular reactivity, metabolism, blood coagulation, capillary permeability, respiration, immune reactions, the hypophyseal-adrenocortical system, ureter, uterus, gastrointestinal tract, brain, bronchial musculature, and immune reactions. He lays special stress upon the production of serotonin in malignant carcinoid, for many symptoms of which serotonin is responsible; and upon the function of serotonin in the brain and its possible relationship to mental processes, normal and abnormal, with allusions to reserpine action and to the possibility of serotonin being a neurotransmitter. Serotonin seems to have a neuro-humoral role in some invertebrates.