[摘要]：of the Na+,K+-ATPase as pos. inotropic compds. Following the previously described model from which istaroxime was generated, the 5a,14a-androstane skeleton was used as a scaffold to study the space around the basic chain of the lead compd. Some compds. demonstrated higher potencies than istaroxime on the receptor and the deriv. (I) was the most potent; as further confirmation of the model, the E isomers of the oxime are more potent than the Z form. The compds. tested in the guinea pig model induced pos. inotropic effects, which are correlated to the in vitro inhibitory potency on the Na+,K+-ATPase. The finding that all tested compds. resulted less proarrhythmogenic than digoxin, a currently clin. used pos. inotropic agent, suggests that this could be a feature of the 3-aminoalkyloxime deriv. class of 5a,14a-androstane.
