Histamine H1 receptor (HRH1) (HRH1)

The Histamine H1 receptor is a G protein-coupled receptor (GPCR) encoded by the HRH1 gene that plays a fundamental role in mediating the effects of histamine in the body [1]. It is primarily coupled to the Gq/11 protein, which activates the phospholipase C pathway to increase intracellular calcium levels [3]. This receptor is widely distributed in the central nervous system, where it regulates wakefulness, and in peripheral tissues such as vascular endothelium and smooth muscle, where it mediates allergic responses [2, 4]. In the context of disease, overactivation of the H1 receptor is a primary driver of allergic rhinitis, urticaria, and anaphylactic reactions by inducing vasodilation and increased capillary permeability [4, 5]. Pharmacological targeting of the H1 receptor involves the use of H1-antihistamines, which typically function as inverse agonists to stabilize the receptor in its inactive state [6]. While newer second-generation antihistamines are designed to be peripherally selective, first-generation agents readily cross the blood-brain barrier, leading to significant sedative effects [2, 6].

Other names

H1 receptorHRH1Histamine receptor H1H1R

Inverse agonism and competitive antagonism [4, 6]