Objectives: Oxidative stress as a result of increased free radical production is implicated in the pathogenesis of several diseases. Specific antioxidant enzymes have a crucial role in the prevention of these deleterious effects. Since the activities of these enzymes differ significantly in different populations and seem to be affected by various environmental factors, in this study we aimed to determine the reference values of glutathione related antioxidant enzyme activities in the erythrocytes of healthy subjects and to investigate the possible variations as a function of age and gender in a healthy Turkish Mediterranean population.
Design and methods: 130 healthy subjects (12-90 yr, 82 females, 48 males) were divided into six different age groups. Erythrocyte glutathione peroxidase (GSH-PX), glutathione reductase (GR) and glutathione-s-transferase (GST) activities were measured on a Hitachi 704 autoanalyser by the modification of previously described manual UV spectrophotometric methods.
Results: No significant differences were observed in erythrocyte GSH-PX, GR and GST activities between different age groups. Overall, GST activities were significantly higher in females compared with males (8.08 +/- 1.39, 6.88 +/- 1.51 U/g Hb respectively, mean +/- SD, p < 0.001). A significant positive correlation between GSH-PX and GR activities was observed (r = 0.49, p < 0.001).
Conclusion: The results of this study suggested that the activities of GSH-PX, GR and GST did not depend. GST activities overall were higher in females. The reference values that we obtained were different than the previous reports. This situation implies that each population should determine its own reference values and should investigate the influence of environmental factors and life style habits on the activities of these enzymes that constitute a major part of the antioxidant defense system in the human organism.