高氧预适应后大鼠抗氧化酶活性及肺组织的变化

背景连续高浓度吸氧可以提高大鼠抗氧化酶,同时对肺产生损伤作用.目的观察间断、高浓度吸氧对大鼠抗氧化酶活性及肺组织的影响.设计完全随机设计,对照实验.单位解放军总医院老年心内科和生化科.材料实验于2002-01/2002-05在海军总医院高压氧科和解放军总医院生化科内完成.选用健康Wister大鼠10只,体质量200～250 g,雌雄不拘.随机将大鼠分为2组,每组5只.方法对照组大鼠在室内环境喂养7d.高氧预适应组动物放人高压氧仓内,每日吸80%～85%的氧气(101.325kPa)6 h,连续7 d.实验结束后取大鼠肺称肺湿重.并取肺组织0.4 g,在冰浴上制成匀浆,取上清液采用化学发光法分别测定超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶活性.将肺组织采用30g/L戊二醛固定,制成切片后电镜下观察肺脏超微结构.主要观察指标①两组大鼠肺湿重及肺组织超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶活性比较.②肺组织超微结构改变.结果大鼠10只均进入结果分析.①肺组织超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶活性高氧预适应组均明显高于对照组[(185.10±1.92)%/g,(90.50±4.17)nkat/g,(4.38±0.18 K/g;(45.15±1.43)%/g,(20.17±2.17)nkat/g,(1.10±0.19)K/g,t=-84.016,-33.488,-28.023,P＜0.01].②大鼠肺湿重高氧预适应组与对照组相近[(1.32±0.07),(1.30±0.03)g,P＞0.05],说明高氧预适应组肺内液体没有增加.③肺组织超微结构高氧预适应组肺组织基膜完整、厚度均匀一致,血管内皮细胞完整,Ⅰ型上皮细胞无破坏.结论间断、高浓度吸氧能提高大鼠肺内抗氧化酶活性,对大鼠肺无明显的损伤作用.

Change on antioxidase and pulmonary tissue in rats after hyperoxic preconditioning

BACKGROUND: Continuous oxygen inhalation of high concentration may improve antioxidase and simultaneously injure the lung in rats.OBJECTIVE: To observe the effect of intermittent high concentration oxygen on antioxidase activity and pulmonary tissue in rats.DESIGN: Complete randomized control experiment.SETTING: Department of Geriatric Cardiology and Department of Biochemistry, General Hospital of Chinese PLA.MATERIALS: The experiment was performed in Department of Hyperbaric Oxygen of Navy General Hospital and Department of Biochemistry of General Hospital of Chinese PLA from January 2002 to May 2002, in which, 10 healthy Wister rats were employed, mass weighted varied from 200 to 250 g, of either sex and randomized into two groups, 5 rats in each.METHODS: In the control, the rats were bred in the room environment for 7 days. In hyperoxic preconditioning (HP) group, the rats were placed in hyperbaric oxygen chamber and inhaled oxygen of 80％ to 85％ (101. 325 kPa) everyday for 6 hours, continuously for 7 days. At the end of experiment, the lung was collected to measure lung wet mass. 0.4 g pulmonary tissue was collected to prepare homogenate in freezing bath and its upper clear solution was collected to determine the activities of superoxide dismutase (SOD), glutathione peroxidase (GTTP) and catalase with chemiluminescence method successively. Pulmonary tissue was fixed with 30 g/L glutaradldehyde and prepared into sections to be observed the microstructure of lung under electron microscope.MAIN OUTCOME MEASURES: ① Comparison of lung wet mass and activities of SOD, glutathione peroxidase and catalase in pulmonary tissue in two groups. ② Alternation on microstructure of pulmonary tissue.RESULTS: Ten rats were all entered result analysis. ① Activities of SOD,GTTP and catalase in pulmonary tissue: Those in HP group were all higher remarkably than the control [(185.10±1.92) ％/g, (90.50±4.17) nkat/g,(4.38±0.18) k/g; (95.15±1.43) ％/g, (20.17±2.17) nkat/g, (1.10±0.19) K/g,t= -84.016, -33.488, -28.023, P ＜ 0.01]. ② Lung wet mass: That in HP group was near to the control [(1.32±0.07), (1.30±0.03) g, P ＞ 0.05], explaining that the fluid in the lung of HP group was not increased. ③ Microstructure of pulmonary tissue: In HP group, the basement membrane of pulmonary tissue was integrative and thickness was even, vascular endothelial cell was integrative and Ⅰ-type epithelial cell was not destroyed.CONCLUSION: Intermittent high concentration oxygen improves antioxidase activity in the lung of rat and does not injure the lung obviously.