title: The effect of helium pressure on guinea-pig isolated tracheal smooth muscle [proceedings].
mesh_terms: D000818:Animals; D001285:Atropine / Q000494:pharmacology; D006168:Guinea Pigs; D009130:Muscle, Smooth / Q000502:physiology*; D011312:Pressure; D013779:Tetrodotoxin / Q000494:pharmacology; D014132:Trachea / Q000502:physiology
chemical_list: D013779:Tetrodotoxin; D001285:Atropine