Glutathione peroxidase activity in iron-deficient rats

The response of glutathione peroxidase (GSH-Px) to dietary iron deficiency was studied in red blood cells and liver from male Sprague-Dawley rats. A casein-based purified diet containing 0.02 ppm Se and 7 ppm Fe was used as the basal diet. Rats were given the basal diet supplemented with either 0.5 ppm Se or 30 ppm Fe or both for 10 weeks. Food consumption in iron-deficient rats was 79% of controls. Iron deficiency caused a significant decrease of GSH-Px and catalase activities in red blood cells (RBC) expressed per cell. However, enzyme activities expressed per gram of hemoglobin or per milligram or protein increased. These data suggest that GSH-Px is present in adequate quantities in iron-deficient red blood cells to protect cell membranes and hemoglobin as long as the rats receive adequate Se. Hepatic catalase was not altered by iron or Se deficiency. Liver Se GSH-Px activity/g tissue decreased to 75% of control activity during iron deficiency. Non Se GSH-Px activity increased during Se or iron deficiencies and may compensate to a limited extent for decreased Se GSH-Px activity. In contrast to earlier reports, RBC GSH-Px activity was not altered by iron deficiency except for possible indirect effects related to changes in red blood cell size or food intake.