title: Control of cardiac-muscle contraction.
mesh_terms: D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D005934:Glucagon / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects*
chemical_list: D005934:Glucagon; D000242:Cyclic AMP; D002118:Calcium