title: Existence of two components in frog cardiac mechanical activity. Influence of Na ions.
mesh_terms: D000818:Animals; D001001:Anura; D001665:Binding Sites; D002118:Calcium / Q000494:pharmacology; D006321:Heart / Q000502:physiology*; D006325:Heart Atria; D006801:Humans; D007477:Ions; D008564:Membrane Potentials / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D012964:Sodium / Q000494:pharmacology
chemical_list: D007477:Ions; D012964:Sodium; D002118:Calcium