title: Determination of femtomole levels of acetylcholine by an improved bioassay procedure.
mesh_terms: D000109:Acetylcholine / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001681:Biological Assay; D003964:Diaphragm / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008722:Methods; D009119:Muscle Contraction / Q000187:drug effects; D010791:Phrenic Nerve / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D013696:Temperature
chemical_list: D000661:Amphetamine; D008274:Magnesium; D000109:Acetylcholine; D011188:Potassium