It is shown that cryptand complexes containing copper inhibit sodium-calcium exchange in sarcolemma of cardiomyocytes. The complexes studied exhibit the superoxide dismutase activity. The binding of copper ions by cryptand prevents the development of cariotoxic effects of the former. Low toxicity, the combined superoxide activity and that inhibiting sodium-calcium exchange of cryptand complexes with copper (II) ions makes the further search for cardioprotective compounds perspective within the series of cryptand copper complexes.