内毒素诱导致敏小鼠建立支气管哮喘动物模型的实验研究

目的 评价用内毒素(LPS)诱导卵清白蛋白(OVA)激发、OVA致敏的小鼠,建立支气管哮喘(简称哮喘)模型的方法.方法 采用随机数字表法将120只BALB/c小鼠分为PBS对照组(A组,PBS致敏PBS激发)、OVA组(B组,OVA敛敏OVA激发)、LPS/LPS小剂量组(C1组,50 μg内毒素致敏50 μg内毒素激发)、LPS/LPS大剂量组(C2组,100μg内毒素敛敏100 μg内毒素激发)、OVA/LPS小剂量组(D1组,OVA致敏、OVA雾化吸入激发结合50 μg内毒素滴鼻诱导)、OVA/LPS大剂量组(D2组,OVA致敏、OVA雾化吸入激发结合100 μg内毒素滴鼻诱导).观察小鼠哮喘急性发作症状,检测BALF细胞分类计数,测定乙酰胆碱激发条件下气道反应性(以肺阻力R_L表示);HE染色观察肺组织病理变化.结果 (1)D1组与D2组小鼠喘息症状加重其中D2组更严重.(2)D1组与D2组BALF中细胞总数、巨噬细胞、淋巴细胞、嗜酸粒细胞、中性粒细胞均明显高于A组(均P<0.05).D1组的白细胞总数、淋巴细胞、嗜酸粒细胞、中性粒细胞均明最高于B组(均P<0.01),D2组的白细胞总数、巨噬细胞、淋巴细胞、中性粒细胞均明显高于B组(均P<0.05).(3)以5 g/L乙酰胆碱激发时,D1组RL(9.32 4±1.51)cm H_2O·ml~(-1)·s~(-1)(1 cm H_2O=0.098 kPa)]和D2组R_L(44.21±2.88)cm H_2O·ml~(-1)·s~(-1)]明显高于A组RL(2.41±0.35)cm H_2O·ml~(-1)·s~(-1)]和B组R_L(5.96±1.83)cm H_2O·ml~(-1)·s~(-1)],均P<0.01.(4)D1组与D2组呈现较为严重的支气管哮喘病变,其中D2组病变程度明显加重.结论 用内毒素诱导OVA致敏小鼠建立支气管哮喘模型的方法可产牛更严重支气管炎症改变以及明显的气道高反应性.

Reproduction of asthma model in ovalbumin-sensitized mice by ovalbumin challenge and lipopolysaccharide induction

Objective To reproduce an asthma model in ovalbumin(OVA)-sensitized Balb/C mice by OVA challenge and Lipopolysaecharide(LPS)induction.Methods One hundred and twenty BALB/C mice were randomly divided into 6 groups:PBS control group(A group,PBS sensitization and PBS challenge),OVA group(B group,OVA sensitization and OVA challenge),low-dose LPS/LPS group(C1 group,50 μg LPS sensitization and 50 μg LPS challenge),high-dose LPS/LPS group(C2 group,100 μg LPS sensitization and 1 00 μg LPS challenge),low-dose OVA/LPS group(DI group,OVA sensitization,OVA thallenge and 50 μg LPS induction)and high-dose OVA/LPS group(D2 group,OVA sensitization.OVA challenge and 100 μg LPS induction).Asthmatic symptoms were observed.Airway responsiveness were assessed and lung resistance(R_L)was calculated using a proprietary software program.Cells in bronehoalveolar lavage fluid(BALF)were counted and lung histopathology was evaluated by HE staining.Results (1) Asthma symptoms in either D1 group or D2 group was more severe than other groups.especially in D2 group.(2)The level of total BALF cells,macrophages,lymphocytes,eosinophils,and neutrophils in either D1 group or D2 group was significantly higher than that in A group(P<0.05,P<0.01).The level of total BALF cells,lymphocytes,eosinophils,and neutrophils in D1 group was significantly higher than that in B group(P<0.01,respectively).The level of total BALF cells,macrophages,lymphocytes,and neutrophils in D2 group wag significantly higher than those in B group(P<0.05,respectively).(3)When mice were stimulated by Ach(5.0 g/L),R_L in either D1 group(9.32±1.51)cm H_2O·ml~(-1)·s~(-1)(1 cm H_2O=0.098 kPa)]or D2 group(44.21±2.88)cm H_2O·ml~(-1)·s~(-1)]was significantly higher than that in A group(2.41±0.35)cm H_2O·ml~(-1)·s~(-1)]and B group(5.96±1.83)cm H_2O·ml~(-1)·s~(-1)](P<0.01,respectively).(4)More marked and extensive asthma-specific changes in lung was observed in either D1 group or D2 group,especially in D2 group.Conclusion LPS induction in OVA-sensitized Balb/C mice can lead to more severe airway inflammation and greater airway hyperresponsiveness. ked and extensive asthma-specific c