急性缺氧大鼠肺组织病理改变和诱导型一氧化氮合酶的表达

Pathological changes of lung tissue and the expression of inducible nitric oxide synthase in acute hypoxia rats

目的:观察急性缺氧时大鼠肺组织损伤和诱导型一氧化氮合酶的分布和活性变化。方法:实验于2004-01/2005-12在齐齐哈尔医学院微形态实验室完成。取Wistar雌性大鼠40只,随机分为正常对照组,缺氧1,3,5,7d组5组,每组8只。缺氧1,3,5,7d组大鼠分别吸入氮气与大气的混合气体(氮气的体积分数为0.95、氧气为0.05)1,3,5,7d建立急性缺氧模型,缺氧每天持续2h,其余时间同正常对照组一样置于常氧下。各组在缺氧完成后进行肺组织取材,进行常规苏木精-伊红染色观察肺组织的形态变化,免疫组织化学染色观察诱导型一氧化氮合酶的染色强度分析。结果:40只大鼠进入结果分析。①苏木精-伊红染色可见缺氧5,7d组肺气肿明显,平均肺泡面积大于正常对照组[(3543.15±150.64),(3724.32±324.67),(2789.12±110.45)μm2,t=9.8913,6.6797,P<0.01]。②随着缺氧时间的延长,诱导型一氧化氮合酶的表达范围逐渐扩大,且其表达的强度也逐渐增强,缺氧5,7d组所有肺组织和肺动脉均为强阳性表达。结论:①急性缺氧可导致大鼠肺组织发生病理改变。②急性缺氧时诱导型一氧化氮合酶在肺组织的表达增多,表达的范围和强度与缺氧时间正相关,与肺组织损伤程度正相关。③诱导型一氧化氮合酶可以作为缺氧程度和肺组织损伤程度的标志之一。

AIM： To explore the damniflcation of lung tissues in rats of acute hypoxia and the action of inducible nitric oxide synthase. METHODS： The experiment was done in the Microstructure Laboratory of Qiqihar Medical College from January 2004 to December 2005. Forty Wistar female rats were randomly divided into 5 groups, normal group and hypoxia 1 d （H1）, 3 d （H3）, 5 d （H5）, 7 d （H7） groups. Rats in hypoxia groups were inhaled with the mixture of nitrogen gas （0.95 volume fraction） and oxygen （0.05 volume fraction） to establish acute hypoxia models, 2 hours every day and normoxia at other points of time that was the same as normal group. After building the model, all groups were selected for lung tissue sections. Hematoxylin-eosin （HE） dyeing was used to observe the morphologic change of lung and immunohistochemistry was used to analyze the dyeing intensity of inducible nitric oxide synthase. RESULTS： All 40 rats were involved in the result analysis.①The result of HE dyeing showed that the comparison of the average pulmonary alveoli area had statistical significance between normal group and H5 or H7 group [（3 543.15±150.64）, （3 724.32±324.67）, （2 789.12±110.45） μm^2, t =9.891 3, 6.679 7, P 〈 0.01].②With the prolong time of hypoxia, the expression of inducible nitric oxide synthase gradually increased in the extent and intensity. Both H5 group and H7 group were strong masculine. CONCLUSION： ①Acute hypoxia can induce pathological changes of lung tissue in rats.②The expression of inducible nitric oxide synthase is increased in lung tissue of rats when they are in acute hypoxia. The area and intensity are both positively related to hypoxia time and the damnification of lung tissue.③Inducible nitric oxide synthase may be one of the signs at degree of hypoxia and damnification of lung tissue.