硫化氢吸入干预大鼠棉花烟雾吸入性肺损伤中的氧化应激

Inhaled hydrogen sulfide inhibits oxidative stress of cotton smoke inhalation-induced acute lung injury in rats

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 , H2 S group, smoke group and smoke ＋H2 S 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 in-haled 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 significant-ly elevated, and those in the smoke ＋H2 S 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 H2 S 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 inhala-tion-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 ox-idative stress and reduces pathological damage to lung tissue .