Decreased erythrocyte nicotinamide adenine dinucleotide redox potential and abnormal pyridine nucleotide content in sickle cell disease

Abstract

RBCs from individuals with sickle cell disease are more susceptible to oxidant damage. Because key antioxidant defense reactions are linked to the pyridine nucleotides nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), we tested the hypothesis that the RBC redox potential as manifested by the NADH/[NAD+ + NADH] and NADPH/[NADP+ + NADPH] ratios is decreased in sickle erythrocytes. Our data demonstrate that sickle RBCs have a significant decrease in the NADH/[NAD+ + NADH] ratio compared with normal RBCs (P < .00005). Interestingly, sickle RBCs also had a significant increase in total NAD content compared with normal RBCs (P < .00005). In contrast, although sickle RBCs had a significant increase in the total NADP content compared with normal RBCs (P