Decreased nadph level impairs the production of nitric oxide(NO) in glucose-6-phosphate dehydrogenase(G6PD) deficient granulocytes

Neutrophil dysfunction and increased susceptibility to infection have been reported in severe G6PD deficiency. The detail mechanism has not been fully elucidated. We have previously repoted impaired production of reactive oxygen species in G6PD-deficient granulocytes(WBCs). Since NO is important in bactericidal process and its generation via NO synthase(NOS) is NADPH dependent, we investigate the NO production in G6PD-deficient WBCs. NO production was determined by measuring nitrite content using the Griess reagent. NOS activity was followed by determining L-[³H] citrulline formation. Our results show that upon stimulation by LPS(5mg/ml) or PMA(10 mM), the production of NO in normal WBCs was eleyated(over 200%) as compared to the resting stage. The NOS activity in the stimulated normal WBCs was also elevated(over 300%). In contrast, G6PD-deficient WBCs did not produce more NO upon stimulation by LPS or PMA comparing to the resting stage. Neither was there any elevation in NOS activity in G6PD-deficient WBCs upon stimulation by LPS or PMA. NOS protein expression by Western blot analysis was similar between normal and G6PD-deficient WBCs. Addition of NADPH to G6PD-deficient cell lysate restored normal NOS activity and NO production. The pathophysiologic implications of this impaired production of NO should be investigated.