title: Antioxidant system and ozone tolerance.
abstract: Rats were initially exposed to 2 ppm ozone for 3 hr in order to induce ozone tolerance. The time course of the content of nonprotein SH as well as the activities of glutathione peroxidase, glutathione reductase, and glucose 6-phosphate dehydrogenase (so-called antioxidant system) in lungs of the animals was compared to the development of tolerance in the animals to a challenge exposure of 5.6 ppm ozone for 3 hr. An enhancement of a part of the antioxidant system was detected on the second day and thereafter following the initial exposure, but the clear and complete tolerance to ozone was demonstrated 1 day before the enhancement of the antioxidant system. Alternatively, the induction of tolerance to ozone was found to be experimentally suppressed by actinomycin D or colchicine, but the levels of the antioxidant system in animals thus treated were not significantly different from the matched controls, or only partly enhanced. These events suggest that the tolerance to ozone is not related to an enhancement of the antioxidant system.
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D003078:Colchicine / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D008168:Lung / Q000201:enzymology*; D010084:Oxidation-Reduction; D010126:Ozone / Q000633:toxicity*; D011654:Pulmonary Edema / Q000139:chemically induced* / Q000201:enzymology / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D013438:Sulfhydryl Compounds; D003609:Dactinomycin; D010126:Ozone; D003513:Cycloheximide; D005954:Glucosephosphate Dehydrogenase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D003078:Colchicine