[Adriamycin-cardiomyopathy induced by an increment of (Ca2+) (author's transl)]

As compared to the metabolic inhibitor 2,4-Dinitrophenol, the cytostatic drug Adriamycin influences the isolated embryo ventricular cells of the chicken, thus causing a decrease in the contraction amplitude, an increase in the heart-rate, and the occurrence of "after-contractions". With radioactive measurements it could be demonstrated, that the reason therefore is an increment of Ca2+i. This may be explained by a decreased Ca-uptake by the sarcoplasmic reticulum and the mitochondria. This increment of Ca2+i brought about a change in the action potential and the refractory-period, as well as the occurrence of "'after-contractions" by control of the potassium flux.