汽油废气颗粒吸入致C57BL/6小黑鼠哮喘样变化

Diesel Exhaust Particulates Induced Asthmatic Reaction in C57BL/6 Mice

目的观察汽油废气颗粒(DEP)吸入在正常小黑鼠是否引起哮喘样变化。方法C57BL/6雄性小黑鼠,随机分为5组,每组15只。A组为对照组,吸入9g/L盐水4周;观察组分B、C、D、E4组,各组分别吸入溶于9g/L盐水的DEP各1、2、3和4周。测定每组小鼠呼吸道阻力,以确定是否产生呼吸道高反应性,比较在支气管肺泡灌洗液中各种炎症细胞变化、血清总IgE、肺组织病理变化、肺组织细胞因子(IFN-γ、IL-5)表达。结果对照组无发生呼吸道高反应性;观察组吸入DEP1周开始出现呼吸道高反应性,每观察组其呼吸道反应性和对照组比较均有统计学意义(F=303.931P<0.01)。且呼吸道反应性随DEP吸入时间延长而增强(r=-0.911P<0.01)。血清总IgE在D组和A组间有统计学意义(F=3.615P<0.01)。支气管肺泡灌洗液中对照组以巨噬细胞为主,DEP吸入1周(B组)后以上皮细胞占大部分,约80%,随DEP吸入,从B组开始出现淋巴细胞浸润,且C、D、E3组淋巴细胞浸润较对照组显著增多(F=468.535P<0.01),淋巴细胞浸润也随DEP吸入时间而增高(r=0.955P<0.001);在病理切片中可观察到随DEP吸入,逐渐出现上皮细胞脱落,呼吸道周围炎症细胞浸润及基底膜纤维化。RT-PCR结果,IFN-γ经DEP吸入2周开始其表达较对照组显著降低(P<0.001),而IL-5表达从DEP吸入3周开始显著增高(P<0.05)。结论DEP吸入可引起C57BL/6小黑鼠TH2淋巴细胞介导的哮喘样炎症反应。

Objective To observe the asthmatic reaction caused by diesel exhaust particulates （DEP） in C57BL/6 mice. Methods C57BL/6 male mice were randomly divided into 5 groups. There were 15 mice of each group. Group A was control group which inhaled saline 4 weeks. Group B, C, D and E respectively inhaled DEF 1 week ,2 weeks ,3 weeks and 4 weeks. Cell changes in bronchialveolar lavage fluid （BALF） and IgE in serum of each group, and observed the pathological changes of inflammatory cells＇ infiltration, epithelial cell＇ shedding, basement membrane＇ fibrosis were observed, the concentration of interferon -γ （ IFN -γ）, interleukin - 5 （ IL - 5 ） of lung tissue were detected by RT - PCR. Results There was no airway hyperresponsiveness in control group. There was airway hyperresponsiveness in the observed group after inhaled DEF 1 week. The airway hyperrespensiveness were significantly different between the control group and each observed group （F=303. 931 Pa 〈0.01 ）.The degree of airway hyperresponsiveness depended on the inhalation time（r= -0. 911 P 〈0.01 ）. The concentrations of IgE in serum were significantly different between group D and group A （ F = 3. 615 P 〈 0.01 ）. There were more macrophages in the BALF of control group. The epithelial cells were 80% after inhaled DEF 1 week in the BALF of group B. Depended on the inhalation time, there was lymphocyte infiltration in group B. The lymphocyte infiltration in group C, D, E were significantly higher than the control group （ F = 468. 535 P 〈 0.01 ）. The lymphocyte infiltration was depending on the inhalation time too （ r = 0. 955 P 〈 0. 001 ）. The lung pathology showed the epithelial shedding,infiltration of peribronchial inflammatory cells, and fibrosis on the basement membrane gradually. While the expression of IFN -γ decreased obviously from group C than group A（ P 〈0. 001 ）, IL - 5 increased from group D than group A（ P 〈0.05 ）. Conclusion Inhalation DEF caused asthmatic inflammatory changes by TH2 lymphocyte.