The subcellular basis for the mechanism of inotropic action of cardiac glycosides.

Actins/biosynthesis Action Potentials/drug effects Actomyosin/biosynthesis Adenosine Triphosphatases/antagonists & inhibitors,metabolism Calcium/metabolism,pharmacology Cardiac Glycosides/metabolism,pharmacology Catecholamines/metabolism Digitalis Glycosides/pharmacology Drug Interactions Heart/drug effects,physiology Membrane Potentials/drug effects Muscle Contraction/drug effects Muscle Proteins/biosynthesis Myocardium/cytology,enzymology,metabolism Myosins/biosynthesis Polymers Potassium/metabolism,pharmacology Sarcoplasmic Reticulum/drug effects Sodium/metabolism,pharmacology Viscosity

Actins Cardiac Glycosides Catecholamines Digitalis Glycosides Muscle Proteins Polymers Actomyosin Sodium Adenosine Triphosphatases Myosins Potassium Calcium