Metabolism in the erythrocytes of dogs with low and high glutathione concentrations

Metabolism of the erythrocytes of high potassium and high glutathione (HK-high GSH), high potassium and low GSH (HK-low GSH) and normal low potassium and low GSH (LK-low GSH) dogs were studied with respect to the levels of enzymes associated with GSH synthesis and metabolism, and the capacity of the cells to regenerate GSH. HK-high GSH dogs were found to have significantly higher levels of hexokinase (Hx) and -glutamylcyclotransferase (GCT) than low GSH groups. The rate of GSH regeneration was much greater in high GSH dogs than in those of low GSH groups, and there is a positive correlation between GSH level and its, regeneration rate. Glutathione-S-transfer-ase (GST) activity was high in both HK-high GSH and HK-low GSH cells. There were no significant differences in the activities of -glutamyl cysteine synthetase (GCS), glutathione synthetase (GSHS) and glutathione reductase (GR) among these three groups. Our results indicate that GSH levels and Hx activity influence GSH regeneration rate, and the GSH levels also affect GST activity.