The synthesis, proof of structure, and biological activity of some new steroidal 17P-formyl guanylhydrazones are described. The guanylhydrazones of nondigitalis-like steroids inhibited myocardial Na+, K+-ATPase but had only a depressant effect on myocardial contractility. By comparison, the corresponding guanylhydrazone of a digitalis-like steroid gave a positive inotropic effect in concentrations that also inhibited Na+, K'-ATPase. The ...
