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Department of Foods and Nutrition, University of Illinois, Urbana, IL 61801
Glutathione peroxidase (GSH-Px) and catalase activities were evaluated during intake of excess dietary iron. Male Sprague-Dawley rats were randomized into seven dietary treatments. The treatments included three levels of dietary iron (35, 305, and 1255 ppm) plus deficiencies of Se or Se and vitamin E at the two high iron levels. Lipid peroxidation in liver and GSH-Px and catalase activities in erythrocytes and liver were measured. Lipid peroxidation was elevated in all high iron groups compared to controls. Total GSH-Px in erythrocytes and liver remained constant or decreased in animals receiving high iron, but non Se GSH-Px increased significantly in liver from rats fed high iron (305 ppm: 155% and 1255 ppm: 131%) and increased additionally in Se and vitamin E deficient groups. No differences in RBC catalase activity were observed. Liver catalase activity increased at least 72% during deficiencies of Se and vitamin E. In summary, GSH-Px did not respond to increased oxidative stress associated with elevated dietary iron except for the non Se GSH-Px which accounts for a relatively small amount of total activity in liver. Catalase increased in liver only when GSH-Px and vitamin E are limiting.
KEY WORDS: iron selenium vitamin E glutathione peroxidase catalase
1 University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642.
2 To whom reprint requests should be sent (University of Illinois address above).
3 Department of Community Health Science, Western Australian Institute of Technology, Hayman Road, Bentley South, Western Australia 6102.
4 Professor of Statistical Design and Analysis, Department of Animal Science, University of Illinois, Urbana, IL.
Manuscript received 26 May 1981.