An apparent acceleration of age-related changes of rat red blood cells by cadmium

The effect of cadmium at nonhemolytic concentrations on rat red blood cells was examined in vitro and compared with that of mercury. When rat red blood cells were incubated at 37 degrees C with 0.5 to 2.0 mM CdCl2 for 60 min, age-related changes of red blood cells occurred. These changes developed in a dose-dependent manner and included increases in cell density and in the number of echinocytes and a decrease in filterability. The incubation of red blood cells with 0.5 and 1.0 mM CdCl2 resulted in their shortened in vivo survival. Neither metabolic blockade, such as a fall in the adenosine triphosphate and glutathione contents, nor potassium leakage occurred at nonhemolytic concentrations of Cd. The effect of HgCl2 on age-related changes of red blood cells occurred at 5- to 20-fold lower concentrations than those of CdCl2. These results show that age-related changes were apparently accelerated by nonhemolytic concentrations of Cd and may be, at least in part, due to the interaction of Cd with thiol residues of cell membranes.