气道滴注与腹腔注射脂多糖建立小鼠急性肺损伤模型的效果比较

Comparative study of efficacy of lipopolysaccharide airway drip versus intraperitoneal injection in induction of mouse acute lung injury models

目的比较脂多糖(lipopolysaccharide,LPS)气道滴注法和腹腔注射法建立的小鼠急性肺损伤(acute lung injury,ALI)模型的效果,为肺内炎症的研究提供实验模型。方法8周龄C57BL/6J小鼠36只,随机分为两组:对照组(PBS)和LPS组,两组分别采用气道滴注和腹腔注射处理。分别采用气道滴注和腹腔注射LPS建立ALI模型。两组小鼠分别采用气道滴注法将LPS(5 mg/kg)或等量体积PBS滴注小鼠气管中;或分别采用腹腔注射法将LPS(5 mg/kg)或等量体积PBS注入小鼠腹腔。气道滴注法给药后4 h和腹腔注射法给药后24 h,分别收集支气管肺泡灌洗液(BALF)检测肺生化指标,检测肺湿/干质量(W/D)比值,观察肺组织病理形态,检测肺组织内炎性因子的表达和肺呼吸功能指标。结果气道滴注LPS组的小鼠肺泡灌洗液总蛋白浓度明显高于腹腔注射LPS组(P<0.05)。肺组织病理切片HE染色显示,LPS组气道滴注诱导的肺损伤较腹腔注射所导致的肺中性粒细胞的浸润增多,肺泡壁增厚,红细胞大量渗出。RT-PCR检测肺组织中炎性因子的表达,与腹腔注射LPS组相比,气道滴注LPS组的ICAM-1和IL-6的mRNA表达量显著增加(P<0.01)。呼吸机检测小鼠的肺功能指标,气道滴注LPS组小鼠的呼吸系统弹性明显高于腹腔注射LPS组,呼吸系统的阻力明显低于腹腔注射LPS组(P<0.05)。结论结合肺组织的生化结果和病理组织切片的结果表明,小鼠ALI模型的建立,气道滴注法优于腹腔注射法。

Objective To compare the efficacy of two models of mouse acute lung injury(ALI)induced by airway drip and intraperitoneal injection of lipopolysaccharide(LPS).Methods Thirty-six 8-week-old C57BL/6J mice were randomly divided into two groups:control group(PBS)and LPS group.ALI models were induce by airway drip and intraperitoneal injection.For the models induced by airway drip,LPS(5 mg/kg)or PBS was instilled into the trachea of mice.For the models of intraperitoneal injection,LPS(5 mg/kg)or PBS was injected into the abdominal cavity of mice.Bronchoalveolar lavage fluid(BALF)was collected at 4 h after airway dripping or at 24 h after intraperitoneal injection to detect lung biochemical indicators,determine the lung wet/dry weight(W/D)ratio,observe the pathological changes of lung tissues,and measure the expression of inflammatory factors and respiratory function indicators.Results The total protein concentration in mouse alveolar lavage fluid in LPS airway drip group was higher than that in intraperitoneal LPS group(P<0.05).HE staining of lung tissue showed that LPS airway drips resulted in more lung neutrophil infiltration,alveolar wall thickening,and red blood cells massive exudation than intraperitoneal LPS.Further biochemical and immunological studies de-monstrated that LPS airway drip resulted in the higher mRNA expression of ICAM-1 and IL-6(P<0.01).The elasticity respiratory system in LPS airway drip group was higher than that in intraperitoneal LPS group,while the resistance respiratory system in LPS airway drip group was lower than that in intraperitoneal LPS group(P<0.05).Conclusion Together with the biochemical and pathological studies of lung tissues,these data demonstrate that ALI induced by airway drips was much more severe than that by intraperitoneal injection.