N-乙酰半胱氨酸对急性肺损伤大鼠环氧合酶2的影响

目的探讨N-乙酰半胱氨酸（N-acetylcysteine,NAC）对急性肺损伤（acute lung injury,ALI）大鼠环氧合酶2（cyclooxygenase-2,COX-2）的影响,进而研究NAC对ALI肺组织的保护作用。方法应用脂多糖诱导大鼠ALI模型,然后应用NAC进行干预。实验设对照组、模型组、NAC组,在肺损伤模型成功后24h处死大鼠,取左叶肺组织。采用免疫组化染色,检测NAC对急性肺损伤大鼠肺组织中COX-2表达的影响,利用HPIAS-2000图像分析系统测定COX-2在以上各组中表达的平均光密度和平均阳性面积率。结果实验中对照组肺组织中COX-2的表达较低;模型组肺组织中COX-2的表达高;NAC组肺组织中COX-2表达较低。经q检验,对照组与模型组之间,COX-2的平均光密度及阳性面积率有显著性差异（P〈0.01）,对照组与NAC组之间,COX-2的平均光密度及阳性面积率差异无显著性（P〉0.05）。结论NAC可以减轻肺损伤的程度,对急性肺损伤组织具有重要的保护作用。

Effect of N-acetylcysteine on Cyclooxygenase-2 in Acute Lung Injury Tissue of Rats

Objective To explore the effect of N-acetylcysteine（NAC）on the expression and clinical significance of cyclooxygenase-2（COX-2）in acute lung injury（ALI）tissue of rats.Methods Lipopolysaccharide（LPS）was applied to induce rats model with ALI.NAC was utilized for intervention.Rats were divided into three groups：contrast group,model group and NAC group.Immunohistochemical staining was performed to detect the expression of COX-2.The average optical density and the rate of positive area of COX-2 expression were analyzed using HPIAS-2000 Analysis System.Results The average optical density and the rate of positive area of the COX-2 expression in contrast group and NAC group were significantly lower than those in model group（P〈0.01）.No significant difference was found in the average optical density and the rate of positive area of COX-2 expression between contrast and NAC groups（P〉0.05）.Conclusion NAC can decrease the expression of COX-2 and hence has protect effect on ALI tissue.