Rahman I, Clerch L B, Massaro D
Lung Biology Laboratory, Georgetown University School of Medicine, Washington, DC 20007.
Am J Physiol. 1991 Jun;260(6 Pt 1):L412-8. doi: 10.1152/ajplung.1991.260.6.L412.
We exposed rats of different ages (weights approximately 45-300 g) to 0.7 ppm O3 for 1-5 days. At 5 days lungs of O3-exposed rats had higher activity of Cu,Zn superoxide dismutase (SOD), Mn SOD, catalase, and glutathione peroxidase than air-breathing rats; this greater activity was not due to blood-associated enzyme activity. The greater enzyme activity occurred with a higher concentration of the mRNA for each enzyme (Mn SOD not measured) without altered stability of these mRNAs. In adult rats the concentrations of these mRNAs were measured after 1, 3, and 5 days exposure to O3 and were elevated by day 3. The intergroup differences (air vs. O3) among antioxidant enzymes (AOEs) were unequal, and the intergroup differences in concentration of the specific AOE mRNA were greater than the differences in activity of their AOE. We conclude exposure to O3 led to greater expression of AOE genes; the increased expression was mediated pretranslationally probably at the level of transcription.
我们将不同年龄（体重约45 - 300克）的大鼠暴露于0.7 ppm的臭氧中1 - 5天。在第5天时，暴露于臭氧的大鼠肺部的铜锌超氧化物歧化酶（SOD）、锰超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶的活性高于呼吸空气的大鼠；这种更高的活性并非源于与血液相关的酶活性。每种酶（未检测锰超氧化物歧化酶）的mRNA浓度更高时，酶活性也更高，且这些mRNA的稳定性未改变。在成年大鼠中，在暴露于臭氧1、3和5天后测量了这些mRNA的浓度，到第3天时浓度升高。抗氧化酶（AOEs）的组间差异（空气组与臭氧组）并不相等，特定AOE mRNA浓度的组间差异大于其AOE活性的差异。我们得出结论，暴露于臭氧会导致AOE基因表达增加；这种增加的表达可能在转录水平上通过翻译前介导。
