Muscarinic acetylcholine receptor M3 (main example; also M2 subtype) (CHRM3, CHRM2)

"Gastrointestinal smooth muscle targets" refers collectively to the variety of molecular entities in GI smooth muscle that regulate contraction and motility, with principal therapeutic focus on muscarinic acetylcholine receptors (M2 and M3 subtypes) which mediate cholinergic contraction in response to acetylcholine released from parasympathetic nerves[1][2][8]. These receptors are G protein-coupled receptors expressed abundantly in GI smooth muscle, where their activation triggers a cascade of signaling events, including inhibition of adenylyl cyclase, phosphoinositide hydrolysis, Ca²⁺ mobilization, and modulation of ion channel activity, all culminating in smooth muscle contraction[1][2]. Other relevant targets include myosin heavy chain (MYH11), L-type calcium channels, and various ion channels and intercellular signaling molecules involved in excitation–contraction coupling[3][4][7]. This terminology is not specific to a single molecule, and as such, any inquiry should target individual molecular entities (e.g., "muscarinic acetylcholine receptor M3") to obtain structured, actionable data. Use of "Gastrointestinal smooth muscle targets" is considered an umbrella term and not a canonical molecular target[1][2][3][4].

Other names

GI smooth muscle targetssmooth muscle muscarinic receptorsgastrointestinal muscarinic receptors(M2/M3 receptors in smooth muscle)

Muscarinic receptor antagonism (relaxes smooth muscle, reduces spasm); Muscarinic receptor agonism (stimulates contraction); Cholinesterase inhibition (increases acetylcholine, stimulates contraction); Calcium channel blockade (suppresses contraction)