title: Circannual variation in sensitivity of the guinea-pig isolated ileum to naloxone.
mesh_terms: D000109:Acetylcholine / Q000502:physiology; D000818:Animals; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009020:Morphine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology*; D012621:Seasons; D013997:Time Factors
chemical_list: D009270:Naloxone; D009020:Morphine; D000109:Acetylcholine