Synchrony of G6PD activity and RBC fragility under oxidative stress exerted at normal and G6PD deficiency

ObjectivesTo investigative the effects of oxidative stress simultaneously on Glucose-6-phosphate dehydrogenase (G6PD) activity and RBC fragility under normal and G6PD defective conditions.MethodsThe effects of several nitric oxide (NO) generating compounds and sulfhydryl blocking agents were simultaneously tested in vitro on hemolysate G6PD activities and RBC fragility. These effects were compared between normal subjects and patients with G6PD deficiency.ResultsThe NO donor compounds nitrosocysteine, nitrosoarginine and diethylamine caused strong inhibition on normal and defective G6PD activities, while a similar inhibition was observed only at higher concentrations of the sulfhydryl blocking agents: 2-mercaptoethanol , cysteine and reduced glutathione. All these oxidative compounds promoted RBC hemolysis in parallel to their inhibition extents on G6PD activities. The protection of RBC from this hemolysis was achieved by preincubation with NADPH or SNP but not NAD+ compound.ConclusionA concomitant response of G6PD activities and RBC fragility towards the oxidative stress was established.