Effect of Selenium Deficiency on Liver and Blood Glutathione Peroxidase Activity in Guinea Pigs

1981 ◽  
Vol 111 (4) ◽  
pp. 690-693 ◽  
Author(s):  
Raymond F. Burk ◽  
James M. Lane ◽  
Richard A. Lawrence ◽  
Paula E. Gregory
Keyword(s):  
Glutathione Peroxidase ◽  
Peroxidase Activity ◽  
Guinea Pigs ◽  
Selenium Deficiency ◽  
Glutathione Peroxidase Activity

Selenium deficiency, endurance exercise capacity, and antioxidant status in rats

1987 ◽  
Vol 63 (6) ◽  
pp. 2532-2535 ◽  
Author(s):  
J. K. Lang ◽  
K. Gohil ◽  
L. Packer ◽  
R. F. Burk
Keyword(s):  
Physical Exercise ◽  
Glutathione Peroxidase ◽  
Peroxidase Activity ◽  
Antioxidant Status ◽  
Acute Exercise ◽  
Selenium Deficiency ◽  
Endurance Capacity ◽  
Glutathione Peroxidase Activity ◽  
Total Glutathione ◽  
Toxic Reactions

Increased O2 metabolism imposed by physical exercise is likely to augment the production of active O2 species that have been shown to react with lipids, proteins, and DNA. Antioxidants and antioxidant enzymes, such as the selenium enzyme glutathione peroxidase, minimize or prevent such potentially toxic reactions. This study shows that selenium deficiency decreases glutathione peroxidase activity in liver and muscle (less than 80%, P less than 0.001), increases total glutathione in liver, muscle, and plasma (P less than 0.05) and increases muscle cytochrome oxidase activity, and ubiquinone content (P less than 0.05) but has no effect on endurance capacity. Exercise to exhaustion resulted in a significant (P less than 0.001) elevation of total and oxidized glutathione (GSSG) and a significant (P less than 0.05) decrease of vitamin E in plasma of control and selenium-deficient rats. Acute exercise also increased tissue GSSG levels in both control and selenium-deficient groups of rats. Hence, despite a large depletion of selenium-deficient glutathione peroxidase, pronounced oxidation of glutathione to GSSG can be produced by the increased oxidative metabolism during physical exercise. The results suggest that the residual glutathione peroxidase activity is sufficient to detoxify hydroperoxides in exercising selenium-deficient animals and to prevent the impairment of endurance capacity.

Selenium and glutathione peroxidase activity in mountain goats

1985 ◽  
Vol 63 (7) ◽  
pp. 1544-1547 ◽  
Author(s):  
Charles T. Robbins ◽  
Steven M. Parish ◽  
Barbara L. Robbins
Keyword(s):  
Glutathione Peroxidase ◽  
Linear Function ◽  
Peroxidase Activity ◽  
Selenium Deficiency ◽  
Selenium Supplementation ◽  
Glutathione Peroxidase Activity ◽  
Oreamnos Americanus ◽  
Domestic Species ◽  
Mountain Goats ◽  
Low Selenium

Blood glutathione peroxidase (GSH-Px) activity in mountain goats (Oreamnos americanus) is a linear function of blood selenium. GSH-Px activity per unit of selenium (Se) in mountain goats is approximately double that published for the domestic cow and horse. It is hypothesized that high GSH-Px activity per unit selenium in mountain goats reduces their dietary selenium requirement relative to the above domestic species and is an essential adaptation for occupying low-selenium environments. GSH-Px activity peaked 20–30 days after injections of 0.1 and 0.3 mg Se/kg. A higher dose of 0.5 mg Se/kg delayed and decreased the development of peak GSH-Px activity relative to the two lower injection groups. When acute pathology owing to a selenium deficiency is demonstrated in wildlife capture programs, passive selenium supplementation, such as with selenium-containing salt blocks, should begin weeks to months before capture to provide adequate time for GSH-Px development.

Response of rat selenoprotein P to selenium administration and fate of its selenium

1991 ◽  
Vol 261 (1) ◽  
pp. E26-E30 ◽  
Author(s):  
R. F. Burk ◽  
K. E. Hill ◽  
R. Read ◽  
T. Bellew
Keyword(s):  
Glutathione Peroxidase ◽  
Peroxidase Activity ◽  
Selenium Deficiency ◽  
Rat Plasma ◽  
Female Rats ◽  
Selenoprotein P ◽  
Glutathione Peroxidase Activity ◽  
Uptake Mechanism ◽  
Male And Female Rats ◽  
And Control

Selenoprotein P is a glycoprotein that contains greater than 60% of the selenium in rat plasma. Physiological experiments were undertaken to gain insight into selenoprotein P function. Selenium-deficient rats were injected with doses of selenium ranging from 25 to 200 micrograms/kg, and the appearance of selenoprotein P was compared with the appearance of glutathione peroxidase activity in plasma and in liver. Selenoprotein P concentration increased to 35% of control by 6 h, whereas glutathione peroxidase activity increased minimally or not at all. Moreover, in rats given 100 and 200 micrograms selenium/kg, selenoprotein P reached 75% of its concentration in control rats at 24 h, whereas glutathione peroxidase activity reached only 6% of control. Cycloheximide pretreatment blocked the appearance of selenoprotein P in response to selenium injection. Male and female rats had similar concentrations of selenoprotein P. Partially purified selenoprotein P and plasma glutathione peroxidase labeled with 75Se were administered intravenously to selenium-deficient and control rats. 75Se given as selenoprotein P disappeared more rapidly from plasma than did 75Se given as glutathione peroxidase. Selenium deficiency did not significantly affect 75Se disappearance from plasma. At 2 h, brain, but not other tissues, took up more 75Se in selenium-deficient rats than in control rats when 75Se was given as selenoprotein P. This suggests that brain has a specific uptake mechanism for selenium given in the form of selenoprotein P. These results demonstrate that several physiological properties distinguish selenoprotein P from glutathione peroxidase. However, they do not clearly indicate its function.

scholarly journals Differences in activities of antioxidant superoxide dismutase, glutathione peroxidase and prooxidant xanthine oxidoreductase/xanthine oxidase in the normal corneal epithelium of various mammals

2007 ◽  
pp. 105-112
Author(s):  
J Kovačeva ◽  
J Pláteník ◽  
M Vejražka ◽  
S Štípek ◽  
T Ardan ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Glutathione Peroxidase ◽  
Xanthine Oxidase ◽  
Peroxidase Activity ◽  
Corneal Epithelium ◽  
Guinea Pigs ◽  
Superoxide Dismutase Activity ◽  
Xanthine Oxidoreductase ◽  
Glutathione Peroxidase Activity ◽  
Oxidoreductase Activity

Under normal conditions, antioxidants at the corneal surface are balanced with the production of reactive oxygen species without any toxic effects. Danger from oxidative stress appears when natural antioxidants are overwhelmed leading to antioxidant/prooxidant imbalance. The aim of the present study was to examine the activities of enzymes contributing to the antioxidant/prooxidant balance in normal corneal epithelium of various mammals. The enzyme activities of antioxidant superoxide dismutase and glutathione peroxidase, as well as prooxidant xanthine oxidoreductase/xanthine oxidase were examined using biochemical methods. Results show that superoxide dismutase activity is high in rabbits and guinea pigs, whereas in pigs the activity is low and in cows it is nearly absent. In contrast, glutathione peroxidase activity is high in cows, pigs and rabbits, whereas in guinea pigs the activity is low. As far as prooxidant enzymes are concerned, elevated xanthine oxidoreductase/xanthine oxidase activities were found in rabbits, lower activities in guinea pigs, very low activity in cows and no activity in pigs. In conclusion, the above results demonstrate inter-species variations in activities of enzymes participating in antioxidant/prooxidant balance in the corneal epithelium. It is suggested that the levels of antioxidant and prooxidant enzymes studied in the corneal epithelium might be associated with the diurnal or nocturnal activity of animals. UV rays decompose hydrogen peroxide to damaging hydroxyl radicals and perhaps for this reason large animals with diurnal activity (cow, pig) require more effective peroxide removal (high glutathione peroxidase activity) together with the suppression of peroxide production (low superoxide dismutase activity, low xanthine oxidoreductase activity).

Low Selenium Status in the Elderly Influences Thyroid Hormones

1995 ◽  
Vol 89 (6) ◽  
pp. 637-642 ◽  
Author(s):  
Oliviero Olivieri ◽  
Domenico Girelli ◽  
Margherita Azzini ◽  
Anna Maria Stanzial ◽  
Carla Russo ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Thyroid Hormones ◽  
Peroxidase Activity ◽  
Controlled Trial ◽  
The Elderly ◽  
Serum Selenium ◽  
Selenium Status ◽  
Glutathione Peroxidase Activity ◽  
Double Blind ◽  
Double Blind Placebo

1. Iodothyronine 5′-deiodinase, which is mainly responsible for peripheral triiodothyronine (T3) production, has recently been demonstrated to be a selenium-containing enzyme. In the elderly, reduced peripheral conversion of thyroxine (T4) to T3 and overt hypothyroidism are frequently observed. 2. We measured serum selenium and erythrocyte glutathione peroxidase (as indices of selenium status), thyroid hormones and thyroid-stimulating hormone in 109 healthy euthyroid subjects (52 women, 57 men), carefully selected to exclude abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects were subdivided into three age groups. To avoid conditions of undernutrition or malnutrition, dietary records were obtained for a sample of 24 subjects, randomly selected and representative of the whole population for age and sex. 3. In order to properly assess the influence of selenium status on iodothyronine 5′-deiodinase type I activity, a double-blind placebo-controlled trial was also carried out on 36 elderly subjects, resident at a privately owned nursing home. 4. In the free-living population, a progressive reduction of the T3/T4 ratio (due to increased T4 levels) and of selenium and erythrocyte glutathione peroxidase activity was observed with advancing age. A highly significant linear correlation between T4, T3/T4 and selenium was observed in the population as a whole (for T4, R = −0.312, P < 0.002; for T3/T4 ratio, R = 0.32, P < 0.01) and in older subjects (for T4, R = −0.40, P < 0.05; for T3/T4 ratio, R = 0.54, P < 0.002). 5. The main result of the double-blind placebo-controlled trial was a significant improvement of selenium indices and a decrease in the T4 level in selenium-treated subjects; serum selenium, erythrocyte glutathione peroxidase activity and thyroid hormones did not change in placebo-treated subjects. 6. We concluded that selenium status influences thyroid hormones in the elderly, mainly modulating T4 levels.

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