Histamine H2 receptor

H₂ receptors are positively coupled to adenylate cyclase via G_s. It is a potent stimulant of cAMP production, which leads to activation of Protein Kinase A. PKA functions to phosphorylate certain proteins, affecting their activity. The drug betazole is an example of a Histamine H₂ receptor agonist.

Function

Histamine is a ubiquitous messenger molecule released from mast cells, enterochromaffin-like cells, and neurons. Its various actions are mediated by histamine receptors H₁, H₂, H₃ and H₄. The histamine receptor H₂ belongs to the rhodopsin-like family of G protein-coupled receptors. It is an integral membrane protein and stimulates gastric acid secretion. It also regulates gastrointestinal motility and intestinal secretion and is thought to be involved in regulating cell growth and differentiation.

Tissue distribution

It is found here:

Physiological responses

Activation of the H₂ receptor results in the following physiological responses: