Inhibition by 5-hydroxytryptamine of anaphylactic histamine release from bovine granulocytes

A suspension of granulocytes from calves sensitised to horse plasma released histamine when exposed to the antigen. Histamine release was strongly inhibited by 5-hydroxytryptamine in a dose-related fashion. 5-HT is known to be released from bovine lungs in vitro, and may regulate the release of histamine in vivo during anaphylaxis.