title: The 5-atom rule and the subclassification of peripheral postsynaptic muscarinic receptors.
abstract: The effects of five pairs of muscarinic compounds in homology relationship within each pair on peripheral postsynaptic muscarinic receptors of rat jejunum and guinea-pig atria and trachea were studied. The relative activities within each pair of compounds were similar for all the biological responses studied. It is reasoned that, at least in the tissues examined, the resemblance between the agonist receptors must be very close.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007583:Jejunum / Q000187:drug effects; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D051381:Rats; D011976:Receptors, Muscarinic / Q000145:classification / Q000187:drug effects*; D014132:Trachea / Q000187:drug effects
chemical_list: D011976:Receptors, Muscarinic; D000109:Acetylcholine