Perspectives in H4R research and therapeutic exploitation

Abstract

Histamine [2-(1H-imidazol-4-yl)ethanamine] is an endogenous short-acting biogenic amine synthesised from the basic amino acid L-histidine through the catalytic activity of the rate-limiting enzyme histidine decarboxylase that is widely distributed throughout the body (Ohtsu, 2010). The classical source of histamine is the pluripotent heterogeneous mast cell, where it is stored in granules and released in response to various immunological and non-immunological stimuli (Kakavas et al., 2006; Riley & West, 1952). Histamine is also produced by a number of other cell types, including gastric enterochromaffin-like cells (Prinz et al., 2003), various types of blood cells, such as basophils (Falcone et al., 2006), macrophages, dendritic cells, lymphocytes (Zwadlo-Klarwasser et al., 1994) and platelets (Masini et al., 1998), chondrocytes (Maslinska et al., 2004), neurons (Lethbridge & Chazot, 2010; Tiligada et al., 2011) and tumour cells (Falus et al., 2001).