Further Studies on Release of Serotonin and Histamine During Anaphylaxis in the Rabbit

Abstract

Serotonin, (5-hydroxytryptamine) in addition to histamine, is liberated into plasma during anaphylaxis in the rabbit. Both serotonin and histamine are found in rabbit platelets and tissues. Reserpine, 0.1 mg/kg, given intravenously causes a release of most of the serotonin and histamine from rabbit platelets within 19 hours but does not change to any great extent the tissue concentrations of these amines. The plasma serotonin levels during anaphylaxis in sensitized rabbits, pretreated with 0.1 mg/kg of reserpine, were not elevated whereas histamine levels were increased. These findings suggest that serotonin is liberated mainly from platelets during rabbit anaphylaxis, but histamine is probably released from both platelets and tissues.