Molecular Aspects of Histamine Receptors

Histamine mediates a multitude of physiological effects in the human body by activating four histamine receptor subtypes. Histamine receptors have proven to be promising drug targets in the treatment of a variety of diseases, including hay fever, gastric ulcers, and inflammatory and neuropathological diseases. In this chapter the molecular aspects of histamine receptors are described, including expression profile, intracellular signaling, and how histamine receptor activity can be modulated by ligands targeting the histamine receptor binding sites. Special attention is given to the possible effect of cellular contexts that might impact the signaling properties of these receptors, like receptor desensitization and internalization, formation of oligomers, and biased signaling. Moreover, insights on the structural effects of antihistamines on the binding affinity and the lifetime of the receptor-ligand compex are discussed.