The effect of the nitrite ion on intact human erythrocytes.

By JOHN D. HARLEY AND HELEN ROBIN T HE CHANGES which result when intact erythrocytes are exposed to the nitrite ion have been studied for almost a century.’6 Such exposure has been found to cause the oxidation of oxyhemoglobin to methemoglobin,26 and of reduced glutathione ( GSH ) to oxidized glutathione ( GSSG ) . .6 In addition, erythrocytes treated with nitrite have been widely used to investigate the factors involved in the reduction of methemoglobin. Despite the breadth of these investigations, certain inconsistencies are still apparent. The results of experiments with erythrocytes from various species have been interpreted to indicate that GSH protects against enzyme inactivation,7 spontaneous hemolysis,8 choleglobin formation9 and Heinz body formation.’#{176}Nitrite-induced GSH depletion might therefore be expected to lead to these changes in vitro, and to excessive hemolysis in vivo. However, the rate of spontaneous hemolysis has been found to be unaffected by the addition of nitrite,6 the evidence as to Heinz body formation is conflicting,4’5 and erythrocyte survival in normal rats has been shown to be unchanged by the administration of nitrite.1’ Previous investigations36 as to the effect of nitrite on the GSH content of intact erythrocytes have been made in the absence of glucose or other source of cellular energy. The present work was designed to study the mode of action of the nitrite ion on intact human erythrocytes, both in the presence and absence of adequate substrate and of a normal pentose phosphate pathway.