Reduced glutathione accelerates the oxidative damage produced by sodium n-propylthiosulfate, one of the causative agents of onion-induced hemolytic anemia in dogs

The oxidative effects of sodium n-propylthiosulfate, one of the causative a gents of onion-induced hemolytic anemia in dogs, were investigated in vitro using three types of canine erythrocytes, which are differentiated by the concentration of reduced glutathione and the composition of intracellular c ations, After incubation with sodium n-propylthiosulfate, the methemoglobin concentration and Heinz body count in all three types of erythrocytes incr eased and a decrease in the erythrocyte reduced glutathione concentration w as then observed. The erythrocytes containing high concentrations of potass ium and reduced glutathione (approximately five times the normal values) we re more susceptible to oxidative damage by sodium n-propylthiosulfate than were the normal canine erythrocytes. The susceptibility of the erythrocytes containing high potassium and normal reduced glutathione concentrations wa s intermediate between those of erythrocytes containing high concentrations of potassium and reduced glutathione and normal canine erythrocytes, In ad dition, the depletion of erythrocyte reduced glutathione by l-chloro-2,4-di nitrobenzene ne resulted in a marked decrease in the oxidative injury induc ed by sodium n-propylthiosulfate in erythrocytes containing high concentrat ions of potassium and reduced glutathione. The generation of superoxide in erythrocytes containing high concentrations of potassium and reduced glutat hione was 4.1 times higher than that in normal canine erythrocytes when the cells were incubated with sodium n-propylthiosulfate. These observations i ndicate that erythrocyte reduced glutathione, which is known as an antioxid ant, accelerates the oxidative damage produced by sodium n-propylthiosulfat e. (C) 1999 Elsevier Science B.V. All rights reserved.