热应激预处理对创伤性休克大鼠早期肺组织中NO、iNOS的表达与肺损伤的影响

Changes of NO and iNOS expression in lung tissues and injury of lungs in traumatic shock rats of early stage preconditioned with heat stress

目的研究热应激预处理对创伤性休克早期大鼠肺组织一氧化氮(NO)浓度、诱导型一氧化氮合酶(iNOS)mRNA表达量与肺组织病理改变的影响。方法 98只SPF级雄性SD大鼠随机分为热应激未处理组和热应激处理组,每组又分别设对照组、休克后0 h组、0.5 h组、1.0 h组、1.5 h组、2.0 h组、3.0 h组7个亚组,每组7只。热应激预处理后建立创伤性休克模型,留取肺组织,观察肺组织病理学和检测肺组织NO浓度、iNOS mRNA表达量的变化。结果病理观察可见热应激处理组各时间点肺病理损伤较热应激未处理组病理损伤轻,肺组织病理学评分较低;NO浓度热应激处理组均低于同时间点热应激未处理组,休克后0 h时均有升高,热应激处理组峰值较未处理组出现晚;iNOS mRNA表达量热应激处理组均低于同时间点热应激未处理组,热应激处理组2.0 h时峰值出现,热应激未处理组则在1.5 h时出现,与肺损伤病理学评分呈正相关。结论热应激预处理能明显降低创伤性休克大鼠早期肺组织中NO、iNOS的表达,推迟和减轻创伤性休克早期大鼠肺损伤。

Objective To research nitric oxide （NO） concentration, induced nitric oxide synthase （iNOS） mRNA expression and the pathological changes of lung tissue in traumatic shock rats of early stage preconditioned with heat stress. Methods A total of 98 male SD rats were equally divided randomly into heat stress untreated group and heat stress treatment group, and each group were equally divided into 7 subgroup： control group and shock 0 h group, 0.5 h group, 1.0 h group, 1.5 h group, 2.0 h group, 3 h group. To established the model of traumatic shock after heat stress pretreatment and remained lung tissue, observed the changes of pulmonary pathology, meas- ured the changes of the NO concentration and iNOS expression in lung tissues. Results The lesions of lung tissue structure were more lighter in heat stress treatment group than the corresponding time point of heat stress untreated group and lung histopathology score lower. The NO concentration of heat stress treatment group were lower than the corresponding time point of heat stress untreated group, the two groups have a rise at shock 0 h, the peak value of NO concentration in heat stress treatment group appeared later than the heat stress untreated group. INOS mRNA expression quantity of heat stress treatment group were lower than the corresponding time point of heat stress un- treated group, the peak value of heat stress untreated group in 2. 0 h and heat stress treatment group in 1.5 h, it was positively correlated with lung injury score. Conclusion Heat stress pretreatment can drop NO concentration and iNOS mRNA expression in lung tissues significantly, delayed and reduced the lung injury in traumatic shock rats of early stage.