[Mechanism of action of positive inotropic substances]

The understanding of the mechanisms of action of positive inotropic substances requires an understanding of the cellular processes of cardiac contraction. The authors then examine the pharmacology of beta-adrenergic receptors and the intracellular functions of cAMP and discuss the action of dopamine, ibopamine, dobutamine, Corwin, amrinone and Vardax. They also summarize the state of the research into the digitalis receptors which revealed the existence of inotropic receptors with high affinity, different from the receptors responsible for inhibition of the Na-K pump. Finally, they discuss the possible role of cardioginine, an endogenous digitalis factor.