Erythrocyte (Ca⁺²+Mg⁺²)‐ATPase activity: Increased sensitivity to oxidative stress in glucose‐6‐phosphate dehydrogenase deficiency

The effect of the thiol‐oxidizing agent diamide on erythrocyte (Ca⁺²+Mg⁺²)‐ATPase activity was measured in normal and glucose‐6‐phosphate‐dehydrogenase‐deficient (G6PD⁻) cells. Although the enzyme activity before the oxidative stress was similar in both groups, diamide induced a markedly greater inhibition in the enzyme activity in the G6PD⁻ cells than in the normal controls. These data indicate dependence of erythrocyte (Ca⁺²+Mg⁺²)‐ATPase, in part, on the redox status of the cell. The increased vulnerability of (Ca⁺²+Mg⁺²)ATPase to oxidative stress in G6PD⁻ may be of pathophysiological relevance to their premature destruction in oxidant‐induced hemolysis.