Effects of low protein diets or feed restriction on rat lung glutathione and oxygen toxicity.
Male rats weighing 200-250 g were fed a 25% casein diet in restricted amounts or ad libitum or one of two low protein diets (3 and 0% casein) ad libitum. Decreased tolerance to hyperoxic stress was observed only in the rats fed low protein diets. These animals had a median death time of 49-50 h compared to 58-69 h for feed-restricted or normal control groups. Death was due to accelerated development of lung edema. Changes in total lung levels of glutathione reductase, glucose-6-phosphate dehydrogenase or catalase did not correlate with oxygen sensitivity. Lung glutathione levels were related to the amount of sulfur-containing amino acids in the diet and were depressed in the feed-restricted as well as the protein-restricted groups. However, feed restriction alone did not enhance oxygen toxicity. We conclude that a decrease in lung glutathione may be partially responsible for the increased oxygen sensitivity in the protein-deficient rats, but that other factors are necessary for explanation of the relative oxygen tolerance of the feed-restricted animals with reduced levels of glutathione in the lung.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001835:Body Weight; D002374:Catalase / Q000378:metabolism; D002149:Energy Intake; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism; D008168:Lung / Q000378:metabolism*; D008297:Male; D010100:Oxygen / Q000633:toxicity*; D011488:Protein Deficiency / Q000378:metabolism*; D051381:Rats
D000596:Amino Acids; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D005980:Glutathione Reductase; D005978:Glutathione; D010100:Oxygen