Effect of high altitude (7,620 m) exposure on glutathione and related metabolism in rats

Reduced and oxidised glutathione (GSH and GSSG) contents, and glutathione r eductase, and glutathione S-transferase activities were studied in the live rs, muscles, and blood/erythrocytes of male Sprague-Dawley rats exposed to intermittent hypoxia (6 h (.) day(-1)) at a simulated altitude of 7,620 m f or 1, 7, 14, and 31 days. Significant decreases in GSH and increases in GSS G contents were observed in the muscles and blood of hypoxia-exposed rats i n comparison to unexposed rats. Significant declines in GSH content by 43% and 45% respectively in muscles and blood were observed in the group expose d for 1 day which tended to recover on subsequent exposure. Glutathione red uctase and glutathione S-transferase activities were decreased in the liver s and erythrocytes of hypoxia-exposed rats, but were increased significantl y in muscle. Lipid peroxidation was also increased in the livers and muscle s of exposed rats. The changes were indicative of an increased production o f reactive oxygen species and an impairment of drug and xenobiotic metaboli sm during exposure to high altitude hypoxia.