Phospholipid hydroperoxide glutathione peroxidase in various mouse organs during selenium deficiency and repletion.
An assay for the determination of the newly discovered selenoenzyme, phospholipid hydroperoxide glutathione peroxidase (PH-GPx) in biological material is described. Dietary selenium deficiency and repletion was used as a tool in order to modify this enzyme activity in various mouse organs and to compare it to the activity of the 'classical' selenium-dependent glutathione peroxidase (GPx) (EC 1.11.1.9). A semipurified diet containing less than 12 ppb Se was used for depletion. Controls received this diet supplemented with 500 ppb Se in the form of Na2SeO3. The results showed that a rapid loss of GPx activity occurred in liver, kidney and lungs of selenium-deficient mice which reached undetectable levels within 130 days. In the heart, about 24% of control GPx activity was still present. In contrast, PH-GPx activity was more slowly depleted by Se deficiency and resulted in residual activities ranging from 30 to 70% in the different organs even after 250 days of depletion. In repletion experiments with a single application of 10 or 500 micrograms/kg Se, only the high dose restored either enzyme activity. The data demonstrate that the need for selenium of the two glutathione peroxidases is different. A markedly distinct organ distribution of both enzymes suggests that the heart may be the organ more sensitive to oxidative stress.
Weitzel
F
F
Faculty of Biology, University of Konstanz, F.R.G.
Ursini
F
F
Wendel
A
A
D000818:Animals; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006321:Heart / Q000187:drug effects; D007668:Kidney / Q000187:drug effects / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008168:Lung / Q000187:drug effects / Q000201:enzymology; D051379:Mice; D008815:Mice, Inbred Strains; D009206:Myocardium / Q000201:enzymology; D009928:Organ Specificity; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D012016:Reference Values; D012643:Selenium / Q000172:deficiency* / Q000494:pharmacology; D013997:Time Factors
D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase; D012643:Selenium