Variations due to hyperoxia and ageing in the activities of glutathione S-transferase and NADPH-cytochrome c reductase.
We have studied the influence of hyperoxia and ageing on the activities of NADPH-cytochrome c reductase and glutathione S-transferase in different rat organs. Lung glutathione S-transferase activity increases markedly in 5-day-old pups exposed to hyperoxia, as observed for the O2- scavenging enzyme, superoxide dismutase. The levels of NADPH-cytochrome c reductase increase as well but after a 3-day lag period. In the liver, there is a pronounced decrease of both activities in 24-month-old rats, but at 12 months the activity of glutathione S-transferase increases whereas that of NADPH cytochrome c reductase activity decreases with respect to 3 months. The pattern of variations with age of NADPH cytochrome c reductase is similar in liver and brain. However the behaviour of brain glutathione S-transferase parallels that of the liver enzyme only up to 12 months. Thereafter the brain activity is maintained at a high level. These observations open the possibility that the high glutathione S-transferase levels in the old rat brain might be involved in protection towards oxidative alterations during ageing.
D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D003579:Cytochrome Reductases / Q000378:metabolism*; D005260:Female; D005609:Free Radicals; D005982:Glutathione Transferase / Q000378:metabolism*; D008168:Lung / Q000201:enzymology; D008264:Macrophages / Q000378:metabolism; D008297:Male; D009245:NADH Dehydrogenase / Q000378:metabolism*; D010100:Oxygen / Q000008:administration & dosage; D051381:Rats; D011919:Rats, Inbred Strains
D005609:Free Radicals; D003579:Cytochrome Reductases; D009245:NADH Dehydrogenase; D005982:Glutathione Transferase; D010100:Oxygen