Muscarinic Acetylcholine Receptor M2 Subtype (M2 mAChR)

The muscarinic acetylcholine receptor M2 subtype (M2 mAChR) is a G protein-coupled receptor (GPCR) that mediates parasympathetic control over various physiological functions. Primarily expressed in the heart, it regulates heart rate, atrial contraction, and AV node conduction. It is also found in airway smooth muscle, the central nervous system, and other tissues, contributing to functions such as movement control, temperature regulation, and olfactory behavior. Activation leads to decreased heart rate via inhibition of adenylate cyclase and activation of potassium channels. Due to its widespread distribution, non-selective antagonists can produce side effects. Autoantibodies against this receptor have been implicated in autonomic disorders.

Other names

M2 receptorCHRM2

Inhibition of adenylate cyclase -> decreased cAMP -> activation of K+ channels