Pharmacology of Histamine, Its Receptors and Antagonists in the Modulation of Physiological Functions

Histamine is an important monoamine consisting of an imidazole ring, which is connected to the amino group by an ethylene group. It is biosynthesized through histidine decarboxylase-catalysed decarboxylation of the amino acid L-histidine. It acts through four different G-protein-coupled receptors in different locations of the body to exert its pharmacological response. There are different structural analogues that have been introduced to activate such receptors, whereas specific antagonists are also introduced to inhibit their effect. This chapter highlights the pharmacology of histamine along with structural biology, biological distribution and physiological role of the different histaminergic receptors within the biological system. Further, this chapter also includes different moderators to the specific histamine receptors and projection for their pharmacological response.