title: Active and passive shortening in voltage-clamped frog muscle fibres.
mesh_terms: D000818:Animals; D001001:Anura; D002794:Choline / Q000494:pharmacology; D066298:In Vitro Techniques; D008564:Membrane Potentials; D009119:Muscle Contraction; D009210:Myofibrils / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D013779:Tetrodotoxin; D002794:Choline