Histamine.

Histamine has at least twenty-three known physiological functions, including playing a prominent role in immunologically mediated inflammation. The structure and metabolism of histamine is discussed, together with the various types of histamine receptors. Histamine plays a role in anaphylaxis, mast cell activation syndromes and mastocytosis and these conditions are relevant to anaesthetic practice. The antihistamine drugs and the H2 receptors agonists are discussed with regard to their role in anaesthesia. [ABSTRACT FROM AUTHOR]