Effect of excess selenium supplementation on the glutathione redox system in broiler chicken.
Selenium, as part of selenocysteine, is the active centre of selenoenzymes. Excess amount of selenium generates oxygen free radicals and reacts with thiol compounds such as reduced glutathione, composing seleno-diglutathione. These reactions impair the amount and/or activity of the biological antioxidant defence system. In the present experiment the effects of two inorganic selenium sources (Na2SeO3, Na2SeO4) on lipid peroxidation and on the content and activity of some components of the antioxidant defence mechanism were studied in Ross 308 hybrid cockerels. In the tissues examined, the glutathione redox system was altered in different ways as an effect of excess selenium. The amount of glutathione and, consequently, glutathione peroxidase activity declined in the blood plasma and in the red blood cell haemolysate, while in the liver malondialdehyde concentration increased only at the end of the experimental period as a result of the boosted enzyme activity. The authors suppose that the cause of increased lipid peroxidation was the potential toxic effect of selenium accumulation above the actual demand.
Balogh
K
K
Department of Nutrition, Szent István University, H-2103 Gödöllo, Páter K. u. 1, Hungary.
Weber
Mária
M
Erdélyi
Márta
M
Mézes
M
M
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D019587:Dietary Supplements; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D064586:Selenic Acid; D018036:Selenium Compounds / Q000008:administration & dosage / Q000633:toxicity*; D018038:Sodium Selenite / Q000008:administration & dosage / Q000633:toxicity*
D018036:Selenium Compounds; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D005978:Glutathione; D018038:Sodium Selenite; D064586:Selenic Acid