不同浓度氧暴露不同时间对新生鼠肺组织一氧化氮生成的影响

目的研究新生鼠暴露于不同浓度氧不同时间肺组织一氧化氮(nitric oxide,NO)含量,内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)和诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)表达的变化.方法四组新生鼠分别暴露于>95%O2、60%O2、40%O2和正常空气(21%O2)中,取暴露12、24、48和72h的肺组织,硝酸还原酶法检测肺组织匀浆中NO含量,免疫组化研究eNOS和iNOS的表达,并采用MIG2000图像分析测量系统进行半定量分析.结果各时相点新生鼠肺组织NO含量、eNOS和iNOS表达与吸氧浓度呈显著正相关(P<0.01),3个高氧组和正常空气对照组NO含量、eNOS和iNOS的表达在部分或全部时相点有显著差异(P<0.05,P<0.01).结论新生鼠暴露于不同浓度氧不同时间对肺组织NO含量、eNOS和iNOS表达均有影响,过量的内源性NO可能与高氧肺损伤有关.

Influence of different concentration oxygen exposure for different time on NO production in lungs of neonatal rats

Objective To study the NO production and expression of eNOS and iNOS in lungs of neonatal rats exposed to different concentration oxygen for different time.Methods Four groups of neonatal rats that were less than 12 hours old were exposed to > 95%O 2,60%O 2,40%O 2 and normal air(21%O 2) respectively,and their lungs tissues were obtained when they were exposed to the corresponding concentration oxygen for 12,24,48 and 72 hours.The NO level was measured by nitrate reductase test.The expression of eNOS and iNOS was studied by immunohistochemisty staining,and semi quantitative analysis was performed by using MIG2000 image analysis system.Results The NO production and expression of eNOS and iNOS in lungs of neonatal rats were positive correlation significantly with the concentration of oxygen inhaled at all the time points( P <0.01),and those of hyperoxia groups were significantly higher than those of normal air control group at some time points( P <0.05, P <0.01).Conclusion Different concentration oxgen exposure for different time influence the NO production and expression of eNOS and iNOS in lung of neonatal rat,and too more endogenous NO maybe correlated with hyperoxic lung injury.