Calcium and the muscarinic receptor.
Pharmacological receptors may be viewed as composed of two linked functions, a recognition site through which the specificity and selectivity of ligand action is expressed and an amplification or catalytic site which translates the ligand-recognition site interaction into response. The successful elucidation of receptor mechanisms requires analysis of both sites. The muscarinic cholinergic receptors of guinea-pig ileal longitudinal smooth muscle will be discussed from this two function stand point and the source and utilization of Ca2+ in excitation-contraction coupling discussed.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D002132:Calcium Radioisotopes; D004148:Dioxolanes / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007811:Lanthanum / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011950:Receptors, Cholinergic / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000187:drug effects*; D013997:Time Factors
D002132:Calcium Radioisotopes; D004148:Dioxolanes; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D007811:Lanthanum; D001285:Atropine; D000109:Acetylcholine; D002118:Calcium