Detrimental effects of Daunorubicin and Doxorubicin on human erythrocytes in vitro

In isotonic medium, daunorubicin in the concentration range of 0.5-5.0 mg/ml of cells and doxorubicin in the concentration range of 0.2-1.0 mg/ml of cells caused hemoglobin (Hb) and K+ to efflux from red blood cells (RBC), to increase RBC size and to lower their deformability. Hb and K+ efflux rates were proportional to the antibiotic concentrations and remained stable for a few hours. Hb efflux did not change significantly in the 4-21 degrees C range (exempt at an experimental concentration of daunorubicin of 5.0 mg/ml of cells) but soared sharply at 37 degrees C. At the daunorubicin and doxorubicin concentration of 0.2 mg/ml of cells, Hb and K+ efflux virtually did not differ from control values. At the antibiotic concentration of 1.0 mg/ml of cells, 37 degrees C, Hb efflux rate was 0.34-5.6%, while that of K+(-) 1.0-8.2%, per hour, of possible maximum value. For the daunorubicin level of 5.0 mg/ml of cells, the respective values were 10 and 17%. At the daunorubicin concentration of 5.0 mg/ml, at 4 degrees C, Hb efflux from RBC was significantly higher than at 21 degrees C. RBC malleability, which was determined as their ability to pass through membrane filters having 3 mm dia pores, did not differ significantly from control values for a few hours antibiotic concentrations not exceeding 0.3 mg/ml of cells. At the antibiotic concentration of 1.0 mg/ml and higher RBC deformability dropped to zero within 10 min. ATP level in RBC practically remained identical to control values during incubation with the antibiotics for several hours.