title: Proceedings: Influence of magnesium on the frequency-force relationship of cardiac ventricular muscle of the guinea pig.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology / Q000502:physiology; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects*; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D010210:Papillary Muscles / Q000187:drug effects
chemical_list: D008274:Magnesium; D002118:Calcium