不同浓度SO_2吸入染毒诱导运动大鼠心肺组织的氧化损伤效应

Oxidative Damage in Heart and Lung Tissue Induced by Sulfur Dioxide Exposure of Different Levels in Exercised Rats

目的研究不同浓度SO2吸入染毒对运动大鼠心肺组织超氧化物歧化酶(SOD)活力、还原型谷胱甘肽(GSH)及丙二醛(MDA)含量的影响,探讨SO2污染对运动者心肺组织损伤的机制。方法48只SD雄性大鼠随机分为8组:空白对照组、单纯运动组、低污染运动组、低污染安静组、中污染运动组、中污染安静组、高污染运动组和高污染安静组。除了空白对照组和单纯运动组,其余各组均置于不同浓度SO2污染环境中(低、中、高污染组SO2浓度分别为5、10、15mg/m3),运动组大鼠进行跑轮运动(8m/min,2h/d,共10d)。24h后处死大鼠,取心肺组织匀浆后立即进行抗氧化酶和脂质过氧化水平测定。结果肺组织SOD活力在高污染运动组、高污染安静组、中污染运动组、中污染安静组、低污染运动组较空白对照组显著降低(P<0.05);心组织SOD活力却出现单纯运动组、中污染安静组升高而高污染安静组、高污染运动组下降的变化趋势(P<0.05)。心肺组织的GSH含量中污染安静组升高而高污染运动组、高污染安静组、中污染运动组下降(P<0.05)。MDA水平各实验组较安静对照组显著升高(P<0.05)。同一浓度污染环境中运动组与安静组相比,SOD活力、GSH含量显著降低,MDA水平显著升高(P<0.05),且存在剂量-效应关系。结论SO2污染可引起大鼠心肺组织的氧化损伤,而SO2污染对运动大鼠心肺组织的氧化损伤效应比安静组更明显。

Objective To investigate the effects of sulfur dioxide （SO2） pollution in different concentrations on activity of SOD, levels of GSH and MDA in heart and lung tissue of exercised rats, in order to elucidate the toxicological mechanism of SO2 pollution. Methods Forty-eight SD rats were randomly divided into eight groups： a rest group （RG）, an exercise group （EG）, a low pollution exercise group （LEG）, a low pollution rest group （LRG）,a moderate pollution exercise group （MEG）, a moderate pollution rest group （MRG）, a high pollution exercise group （HEG） and a high pollution rest group （HRG）.All groups, except RG and EG, were exposed to SO2 with different concentrations （5 mg/m^3,10 mg/m^3, 15 mg/m^3）, meanwhile exercised rats run in a motor-driven wheel at a speed of 8m/min,2 h/d for 10 days. Rats were sacrificed at 24 h after treatment and the anti-oxidative enzymes activity and lipid peroxidation （LPO） levels were measured. Results Compared with RG, SOD activity of lung tissue significantly decreased in HEG, MEG, LEG （P〈0.05）, whereas the change of SOD activity of heart showed a tendency that EG, MRG raised and HRG,HEG declined （P〈0.05）.GSH levels of heart and lung tissue appeared a conspicuous increase in MRG and a noticeable decrease in HEG,HRG,MEG （P〈0.05）. MDA levels of heart and lung tissue in each group had a significant increase in comparison with RG （P〈0.05）. Compared with the rest group in the same polluted environment, SOD activity and GSH levels of heart and lung tissue in exercise groups had a markedly decrease while MDA levels significantly increased （P〈0.05）, with a dose-dependent manner. Conclusion SO2 exposure can induce oxidative damage in exercised rats＇ heart and lung tissue, which is more significant than rest rats.