Studies of enzymes connected with erythrocyte glutathione metabolism in a rural tropical population.

Abstract

The activities of the erythrocyte enzymes hexokinase (HK), glucose-6-phosphate dehydrogenase (G-6-PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR) and glutathione peroxidase (GSH-PO) were determined in a group of 12 Europeans and in a group of 103 male Thai subjects in northern Thailand. In the Thai group there were 16 subjects with G-6-PD deficiency and 28 subjects with abnormally low levels of GR activity. A comparison of the enzyme activities in the different subgroups indicated that HK and 6-PGD are not influenced by G-6-PD deficiency whereas GR and GSH-PO activities are significantly higher in G-6-PD deficient subjects. In the group with low GR activity G-6-PD and GSH-PO showed a tendency to an elevation of activity when compared with the normal control group. Significant positive correlations exist between G-6-PD and 6-PGD in the normal group and between GR and GSH-PO in the G-6-PD deficient group. A negative correlation between GR and GSH-PO was present in the group with low GR activities. A study of the families of subjects with low activity of GR did not yield evidence for the existence of a deficiency polymorphism.