[Direct action on the isolated frog heart of some biological substances involving cardiac metabolism. Chronotropic and inotropic effects].
D000818:Animals; D001001:Anura; D003067:Coenzymes / Q000494:pharmacology*; D006321:Heart / Q000494:pharmacology*; D009525:Niacin / Q000031:analogs & derivatives; D009539:Nicotinic Acids; D011898:Ranidae
D003067:Coenzymes; D009539:Nicotinic Acids; D009525:Niacin
COENZYMES/pharmacology; HEART/pharmacology; NICOTINIC ACID/related compounds