Histamine
Chapter: 2
Beta-aminoethylimidazole. A vasoactive amine that acts by interacting with two kinds of receptors, H1 or H2. The former receptors appear to be most important in the induction of increased vascular permeability, which is largely due to contraction of endothelial cells in postcapillary venules. Both kinds of receptors are involved in causing vasodilitation. Histamine is the principal cause of the acute-transient vascular phenomena that are responsible for producing the triple response reaction (see separately).