Bhandari V, Maulik N, Kresch M
Department of Pediatrics, University of Connecticut School of Medicine, Farmington, USA.
Lung. 2000;178(1):53-60. doi: 10.1007/s004080000006.
It is well known that exposure to hyperoxia results in lung inflammation and damage, which leads to the development of chronic lung disease. Previous studies have shown increased activities of antioxidant enzymes (AOE) in lung tissue from animals exposed to hyperoxia. We propose the hypothesis that the fetal type II pneumocytes (TIIP) would be resistant to oxygen toxicity by virtue of increasing AOE activity on exposure to hyperoxia. The aim of this study was to measure the activities of catalase, glutathione reductase, glutathione peroxidase (GPX), and cytosolic superoxide dismutase (SOD) in cultures of adult and fetal rat TIIP exposed to 95% oxygen for 24 h. Control cells were incubated in room air. Hyperoxia exposure resulted in 53.4 +/- 1.2% of control viability (mean +/- S.E.M.; p = 0.001) in the adult TIIP with a significant threefold increase in the activities of all the AOE. The fetal TIIP were more resistant to hyperoxia (99.4 +/- 6.1% of control viability). However, in the fetal TIIP, only SOD and GPX levels were significantly increased (fourfold and 2.3-fold, respectively) compared with fetal controls. We conclude that fetal TIIP are more resistant to hyperoxia than adult TIIP in terms of viability; other protective antioxidant factors might account for the better survival of fetal TIIP in hyperoxia.
众所周知，暴露于高氧环境会导致肺部炎症和损伤，进而引发慢性肺病。先前的研究表明，暴露于高氧环境的动物肺组织中抗氧化酶（AOE）的活性会增加。我们提出一个假设，即胎儿II型肺细胞（TIIP）由于在暴露于高氧环境时AOE活性增加，因而对氧毒性具有抗性。本研究的目的是测量成年和胎儿大鼠TIIP细胞培养物在暴露于95%氧气24小时后过氧化氢酶、谷胱甘肽还原酶、谷胱甘肽过氧化物酶（GPX）和胞质超氧化物歧化酶（SOD）的活性。对照细胞在室温空气中孵育。高氧暴露导致成年TIIP细胞的活力为对照的53.4±1.2%（平均值±标准误；p = 0.001），且所有AOE的活性显著增加了三倍。胎儿TIIP对高氧更具抗性（活力为对照的99.4±6.1%）。然而，与胎儿对照相比，胎儿TIIP中只有SOD和GPX水平显著升高（分别为四倍和2.3倍）。我们得出结论，就活力而言，胎儿TIIP比成年TIIP对高氧更具抗性；其他保护性抗氧化因子可能是胎儿TIIP在高氧环境中存活率更高的原因。
