Effects of NADH and H2O2 on chromate-induced human erythrocytes hemoglobinoxidation and peroxidation

The effects of NADH and H2O2 on chromate-induced human erythrocyte hemoglob in oxidation and peroxidation were studied. It was observed that NADH decre ases the levels of chromate-induced human erythrocyte hemoglobin oxidation and peroxidation. H2O2 decreases the levels of chromate-induced hemoglobin oxidation, but increases the levels of chromate-induced peroxidation. The a bility of H2O2 to decrease the levels of chromate-induced hemoglobin oxidat ion is higher than that observed for NADH. Furthermore, H2O2 increases the inhibitory effect of NADH on chromate-induced hemoglobin oxidation, but dec reases the NADH effect on chromate-induced peroxidation. The meaning of the se results is discussed in terms of involvement of reactive chromium(V) spe cies and reactive oxygen species in the mechanism by which chromate induces its effects in human erythrocytes. (C) 2000 Academic Press.