Histamine H1 Receptors

Histamine H1R (HRH1) is a G-protein coupled 7-transmembrane putative glycoprotein that is implicated in the pathogenesis of asthma and is a major pharmaceutical target for antihistamines. It has been detected as a mixture of monomers and homodimers, with highest concentration in the placenta, followed by brain, lung (produced by airway smooth muscle, bronchial epithelium and macrophages) and other tissues.