中文摘要：

目的探讨还原型烟酰胺腺嘌呤二核苷酸（NADH）脱氢酶亚单位1、2、5在早产大鼠高氧肺损伤组织中的动态表达及其意义。方法早产新生大鼠生后1d随机分为高氧和空气组，高氧组持续暴露于850mL／L氧气中，空气组置同一室内常压空气中。分别取二组大鼠高氧或空气暴露后1、4、7、10和14d肺组织标本，采用HE染色观察肺组织形态学改变，采用RT—PCR法在mRNA水平检测NADH脱氢酶亚单位1、2、5的表达。结果1，高氧暴露1、4d，早产大鼠肺组织形态较空气组无明显改变；高氧暴露7、10d，肺组织渐出现小血管充血扩张，肺泡腔内炎性细胞浸润，肺泡间隔增厚，肺泡数目减少、结构简单化和囊泡化等改变。2．空气组NADH脱氢酶亚单位1（ND1）和亚单位2（ND2）mRNA的表达随日龄增长渐降低，至7d时最低，随后其表达逐渐增高；空气组NADH脱氢酶亚单位5（ND5）mRNA的表达随日龄增长渐降低，至4d时最低，随后其表达逐渐增高。3．与同时间点空气组相比，高氧暴露后1、4和7dND1和ND5mRNA表达显著增强（Pa〈0．05），随后其表达渐下降，10、14d时低于空气组，但二者相比差异无显著性意义（Pa〉0，05）；与同时间点空气组相比，高氧暴露后1、4dND2mRNA表达二组间差异无显著性意义（Pa〉0．05），7d时较空气组极显著增强（P〈0．01），10、14d时较空气组显著降低（P。〈0．05）。结论高氧可导致早产大鼠肺组织NADH脱氢酶表达改变，提示其可能参与高氧肺损伤的病理生理过程。

英文摘要：

Objective To explore the temporal expression of reduced nicotinamide adenine dinucleotide（NADH） dehydrogenase subunit 1, 2,5 in lung of premature rats with hyperoxia - induced lung injury and its significance. Methods Premature Sprague - Draw rats were randomly assigned to hyperoxia group and air group at 1 d after birth. These rats in hyperoxia group were persistently exposed to 850 mL/L oxygen and those in air group to room air. The lung tissues of both groups were collected at 1,4,7,10 and 14 d after being exposed to hyperoxia or air. The lung histological changes were observed by HE staining, and the expression of NADH dehydrogenase subunit 1,2,5 mRNA were detected by semi -quantitative reverse transcription polymerase chain reaction （ RT - PCR）. Results 1. There were no lung histological changes in hyperoxia group before the 4 d after being exposed to hyperoxia,then the lung in hyperoxia group gradually existed a series pathological histological changes. 2. The expressions of NADH dehydmgenase subunit 1 （ND1） and subunit 2 （ND2） mRNA in air group gradually decreased with age, the lowest at 7 d ,then it gradually increased ; the expression of NADH dehydmgenase subunit 5 （ ND5 ） mRNA in air group gradually decreased with age, the lowest at 4 d, then it gradually increased. 3. Compared with air group, the ND1 and ND5 mRNA levels in hyperoxia group were significantly higher （ Pa 〈 0.05 ） at 1,4 and 7 d, then it gradually decreased, lower than air group at 10 and 14 d, but there was no significant difference （Pa 〉 0.05 ） ;compared with air group, the ND2 mRNA level in hypemxia group had no obvious changes at 1 and 4 d, increased significantly at 7 d （ P 〈 0.05 ）, and then decreased significantly at 10 and 14 d （Pa 〈 0.05 ）. Conclusion Hyperoxia induces the expression of NADH dehydrogenase in premature rat lung,this indicates that this may participate in the physiological and pathology processes of hyperoxia- induced lung injury.