目的探讨吸入硫化氢(hydrogen sulfide, H₂S)干预大鼠棉花烟雾吸入性肺损伤的氧化应激反应机制。方法24只雄性SD大鼠随机分成对照组、H₂S组、烟雾组、烟雾+H₂S组,每组6只。复制大鼠棉花烟雾吸入性损伤模型,在烟雾吸入或模拟烟雾吸入后,H₂S组、烟雾+H₂S组大鼠予以持续吸入H₂S 80 ppm+30%氧气6 h,对照组、烟雾组予以吸入30%氧气6 h,ELISA法检测肺组织匀浆中MDA、NO、iNOS、NF-κB p65浓度,免疫组化检测肺组织NF-κB p65并进行半定量分析,荧光定量PCR法行肺组织iNOS mRNA定量。结果烟雾组大鼠肺组织匀浆中MDA、NO、iNOS、NF-κB p65浓度和肺组织中NF-κB p65的累积光密度、iNOS mRNA的相对表达量均明显高于对照组,而烟雾+H₂S组的上述指标较烟雾组均明显降低,如肺组织匀浆中NF-κB p65浓度(8123.51±2095.33)　pg/ml vs (13803.19±2196.37)　pg/ml,P<0.001;肺组织中iNOS mRNA的相对表达量(1.04±0.24) vs (2.20±0.21),差异有统计学意义(P<0.001);H₂S组iNOS浓度、iNOS mRNA的相对表达量、NF-κB p65的累积光密度高于对照组,但MDA、NO、iNOS、NF-κB p65浓度与对照组比较无明显差别。结论吸入H₂S的干预机制可能是吸入H₂S可抑制NF-κB p65的激活,使iNOS mRNA的转录合成减少,从而减少iNOS、NO生成,减轻氧化应激反应和减轻大鼠肺损伤。

Objective To investigate the mechanisms of inhaled hydrogen sulfide inhibiting oxidative stress of cotton smoke inhalation-induced acute lung injury in rats. Methods Twenty-four male SD rats were randomly allocated into control group, H₂S group, smoke group and smoke+H₂S group. The rat model of cotton smoke inhalation injury was established. After smoke inhalation or simulated smoke inhalation, rats inhaled H₂S 80 ppm, 30% oxygen for 6 hours (H₂S group and smoke+H₂S group), or rats inhaled 30% oxygen for 6 hours (control group and smoke group). Then rats were mercy killed. In each group of rats we observed the concentration of NO,iNOS,NF-κB p65,MDA in homogenized lung tissue by ELISA,used the method of fluorescence quantitative PCR to detect the expression of iNOS mRNA in homogenized lung tissue, and immunohistochemically detected the relative expression of NF-κB p65 with Image Pro Plus 6.0 software. Results Compared with the control group, concentrations of MDA, NO, iNOS, NF-κB p65, relative expression of iNOS mRNA and sum IOD of NF-κB p65 in the smoke group rats’ homogenized lung tissue were significantly elevated, and those in the smoke+H₂S group were relatively lower, for example, concentrations of NF-κB p65 were (8123.51±2095.33) pg/ml vs (13803.19±2196.37) pg/ml, P＜0.001; relative expression of iNOS mRNA was (1.04±0.24) vs (2.20±0.21), P＜0.001. Concentrations of iNOS, relative expression of iNOS mRNA and sum IOD of NF-κB p65 in the H₂S group were higher than those in the control group, meanwhile concentrations of MDA, NO, NF-κB p65 in the H₂S group were similar to those in the control group. Conclusions The mechanisms of inhaled 80 ppm hydrogen sulfide for 6 hours protecting against cottn smoke inhalation-induced ALI in rats potentially is inhaled hydrogen sulfide inhibiting the activation of NF-κB p65, so the expression of iNOS mRNA, iNOS and NO grow downwards and as a result, it relieves oxidative stress and reduces pathological damage to lung tissue.