Glutathione peroxidase activities during selenium depletion of adult female rats and during selenium repletion of their offspring.
The main purpose of the present investigation was to produce young rats with severe selenium deficiency, but with no clinical signs of this deficiency, and to examine their liver and red blood cell (RBC) glutathione peroxidase activities during selenium repletion. To achieve this goal, female breeders were fed a selenium-deficient diet beginning 2 weeks before mating. The liver glutathione peroxidase activity of the dams was significantly lower than the activity of comparable nonpregnant females after 5 and 10 weeks of selenium depletion. This difference arose exclusively during the period of pregnancy. In contrast, the RBC glutathione peroxidase activity was significantly increased during this period. Only traces of liver enzyme activity were found in the offspring, and the RBC enzyme activity was only 2% of that of the selenium-repleted controls. Body weight was retarded in the male offspring. However, no severe signs of clinical selenium deficiency were observed. The glutathione peroxidase activity in the liver and RBCs of the offspring was determined after 0, 2, 4, 7, 14, and approximately 40 days of selenium repletion. The liver enzyme activity increased faster in females than in males, while the opposite was found for the RBCs. After 14 days of selenium repletion, the glutathione peroxidase activity of the liver was essentially restored, and the RBC enzyme activity was about half that of the control values. This type of rat may prove useful in studies in which young selenium-deficient rats are preferable, as well as in studies of selenium functions that might not be directly related to the role of selenium in glutathione peroxidase.
Olsson
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Department of Genetic and Cellular Toxicology, Wallenberg Laboratory, University of Stockholm, Stockholm, Sweden.