title: Mechanism of variation in the action of acetylcholine in isolated frog hearts.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001001:Anura; D002302:Cardiac Output / Q000187:drug effects; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D004562:Electrocardiography; D006321:Heart / Q000187:drug effects*; D006329:Heart Conduction System / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D011950:Receptors, Cholinergic; D012621:Seasons; D012849:Sinoatrial Node / Q000187:drug effects; D013268:Stimulation, Chemical
chemical_list: D011950:Receptors, Cholinergic; D000109:Acetylcholine