title: Letter: Biphasic responses to guanosyl nucleotides in two smooth muscle preparations.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D006152:Cyclic GMP / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D013268:Stimulation, Chemical; D014132:Trachea / Q000187:drug effects
chemical_list: D006152:Cyclic GMP; D000109:Acetylcholine