n-3多不饱和脂肪酸对运动性哮喘豚鼠气道炎症和气道高反应性的影响

Effect of n-3 Polyunsaturated Fatty Acid on the Airway Inflammation and Airway High Reactivity in Guinea Pigs with Exercise-induced Asthma

目的:探讨n-3多不饱和脂肪酸(n-3PuFA)对运动性哮喘(EIA)豚鼠支气管肺灌洗液(BALF)、肺组织病理学、气道阻力和动态肺顺应性的影响及其可能机制。方法:20只豚鼠随机分为正常对照组(n=6)、EIA模型组(n=7)和EIA+n-3PuFA干预组(n=7)。实验第1、14天对照组腹腔注射生理盐水,其它两组腹腔注射脂多糖(Lipopolysaccharide,LPS)+甲双吡丙酮(Metyrapon1,MET)。n-3PuFA干预组每天给予n-3PuFA液灌胃(0.04g/kg),对照组和EIA模型组补充同剂量的蒸馏水。各组豚鼠在第21天测试气道阻力(RL)和动态肺顺应性(Cydn),建立运动性哮喘模型后麻醉处死,取豚鼠肺组织观察BALF细胞总数及分类、豚鼠气道反应性及肺组织形态学的变化。结果:EIA模型组豚鼠BALF中细胞总数、嗜酸性粒细胞(EOS)显著高于对照组(P<0.01);RL显著性增高,Cydn明显下降(P<0.05);肺组织可见嗜酸性粒细胞、中性粒细胞和淋巴细胞等炎性细胞浸润。EIA+n-3PuFA干预组豚鼠BALF中细胞总数、EOS显著低于EIA模型组(P<0.05),气道阻力RL呈下降趋势,Cydn表现出升高趋势;支气管粘膜上皮伴少许炎性细胞浸润。结论:运动性哮喘存在气道粘膜的炎症改变和气道高反应性,n-3PuFA可以通过减少气管粘膜炎性介质的产生改善EIA的通气情况。

Objective To investigate the effect of applying n-3 polyunsaturated fatty acids（n-3PuFA） on the bronchial lung lavage fluid（BALF）,lung tissue,airway resistance,and dynamic pulmonary compliance in guinea pigs with exercise-induced asthma（EIA）.Methods Twenty guinea pigs were randomly divided into normal control group（n=6）,EIA model group（n=7）and EIA＋n-3PuFA intervention group（n=7）.The control group was intraperitoneally injected with normal saline,and the others were intraperitoneally injected with lipopolysaccharide（LPS）＋Metyrapon1（MET）on the 1st and 14th day.n-3PuFA intervention group was intragastrically administrated with n-3PuFA every day,and the control group and EIA model group were supplemented by the same amount of distilled water.Airway resistance and dynamic lung compliance in all groups were detected on the 21st day.Following completion of experiment,the lung tissue was removed for determining the total number of BALF cells and cells classification,and airway reactivity and the changes in lung histomorphology were observed.Results The total number of cells and eosinophils（EOS）in BALF of EIA model group were significantly higher than that of control group（P 0.01）.Airway resistance significantly increaseed,while dynamic lung compliance significantly decreased（P 0.05）.Infiltration of inflammatory cells（EOS,neutrophils,lymphocytes and others） revealed in the lung tissue.The total number of cells and EOS in BALF of EIA＋n-3PuFA intervention group decreased significantly as compared with that of EIA model group（P 0.05）.Airway resistance tended to decrease,while dynamic lung compliance tended to increase.There was a light infiltration of inflammatory cell in the epithelium mucosae of tunica mucosa bronchiorum.Conclusion Inflammatory changes in airway mucosa and airway hyperreactivity were seen in EIA,and n-3PuFA could improve the ventilation conditions of guinea pigs with EIA by reducing the production of inflammatory mediators in tunica mucosa tracheae.