氧化失衡在免疫受损大鼠肺部感染发病机制中的作用

目的　探讨氧化 /抗氧化系统的失衡在免疫受损宿主 (ICH)肺部感染发病机制中的作用。方法　以清洁级SD大鼠为研究对象 ,建立ICH模型及其肺部感染模型 ,以正常大鼠作为对照 ,观察感染前、后共 7个时间点的各种指标 ,包括氧化 /抗氧化指标 ,肺组织细菌负荷 ,肺血管渗透性指标和肺湿干比 (W/D) ,肺组织病理学等。结果　ICH组丙二醛 (MDA)明显高于对照组 ,肺组织细菌负荷逐步升高不回落 ,肺血管渗透性和肺W/D均明显高于对照组 ,而超氧化物酶 (SOD)明显低于对照组。肺组织病理学显示ICH组肺损伤严重 ,肺充血、出血明显 ,肺上皮细胞凋亡小体形成。结论　ICH肺部感染时存在严重的氧化 /抗氧化系统的失衡 ,氧化 /抗氧化系统的失衡在ICH肺部感染的肺损伤中可能起重要作用。

The imbalance of oxidant-antioxidant system in pneumonia of immunocompromised rats

Objective To observe the mechanisms and significance of imbalance of oxidant-antioxidant system in pneumonia of immunocompromised host (ICH).Methods Sprague-Dawley rats were used to establish immunocompromised model with pneumonia.Bacterial loading,superoxide dismutase,malondialdehyde,pulmonary vascular permeability/edema,and pulmonary histopathology were observed at different time points.Results The level of superoxide dismutase in the ICH rats was lower than that in the control group while malondialdehyde was much higher than that in the control group.Pulmonary vascular permeability and wet/dry ratio of ICH were more obvious compared to the control.Pulmonary histopathology of ICH pneumonia revealed serious lung injury,pulmonary congestion and hemorrhage.Conclusion There is a serious imbalance of oxidant-antioxidant system in pneumonia of ICH,which may play an important role in the pathogenesis of lung injury.