肺表面活性物质对大鼠肺损伤后氧合功能的影响

目的和方法：本研究利用氧自由基所致的大鼠肺损伤模型，对肺损伤后肺表面活性物质（ＰＳ）病理改变和外源性ＰＳ替代治疗的作用进行了探讨。结果：大鼠气道滴入黄嘌呤和黄嘌呤氧化酶２４ｈ后，ＰａＯ２和胸肺顺应性显著下降；肺系数明显增高，组织学观察可见炎症性肺水肿。肺支气管灌洗液分析结果表明ＰＳ含量减少，蛋白含量增高。应用外源性ＰＳ治疗后，ＰａＯ２从处理前３２４±８６ｋＰａ上升到４７５±２９ｋＰａ（Ｐ＜００１）。结论：（１）肺损伤后的不同阶段ＰＳ的病理变化可能是不一致的；（２）外源性ＰＳ的替代治疗有明显效果。

The improvement of oxygenation of injuried lungs by exogenous surfactant replacement in rats

AIM and METHOD:The change of lung function induced by oxygen free radicals and effect of exogenous surfactant replacement on oxygenation of injuried rat lungs were studied.RESULTS:P aO 2 and lung-thorax compliance measured after intratracheal instillation of xanthine and xanthine oxidase were significantly reduced.In morphological study,the increase of lung weight to body weight ratio was demonstrated,and there were perivascular edema and infiltration with neutrophils microscopically.The analysis of bronchoalveolar lavage fluid showed a reduction of surfactant and an increase of protein content.After surfactant administration to injured rats,the lung oxygenation was highly improved with an increase of P aO 2 from a means of 32.4 kPa to 47.5 kPa( P <0 01).CONCLUSION:The changes of pulmonary surfactant content differ in the stage of lung injury and that exogenous surfactant replacement therapy might be a rational approach to the treatment of acute respiratory failure caused by various factors.