The autofluorescence due to lipofuscin bodies was investigated in cardiac miocytes of young adult mice treated with oxamniquine. The aim was to detect evidence for a cell aging process promoted by the drug, taking into account previous findings on the enhancement of polyploidy in this material. However, as no lipofuscin was observed in these cells, when compared to young and old control animals, it is assumed that the efficiency of the lysosome lipases in the heart miocytes of the treated mice is not affected by the drug induced polyploidy enhancement.