Serotonin and Histamine Release During Anaphylaxis in the Rabbit

The release of physiologically active substances in animal tissues during anaphylaxis has been a subject of considerable interest for many years. Most of this interest has centered on the release of histamine from a bound to a free form, the latter being capable of producing marked physiological changes (1). However, despite the toxicity which can be attributed to histamine, attempts to explain all the alterations seen in anaphylaxis on the basis of histamine release alone have been unsatisfactory (2). Many of the effects produced by serotonin (5-hydroxytryptamine) in animals (3) resemble the manifestations of hypersensitivity reactions. In addition, patients with malignant carcinoid, a syn