降钙素基因相关肽和P物质在臭氧加重小鼠过敏性哮喘中的作用

Role of calcitonin gene-related peptide and substance P on ozone-exacerbated allergic asthma in mice

目的探讨降钙素基因相关肽(CGRP)和P物质(SP)在臭氧加重小鼠过敏性哮喘中的作用。方法将24只SPF级Balb/c小鼠随机分为对照组(生理盐水)、卵清蛋白(OVA)致敏组和OVA+O3暴露组(OVA+2.14 mg/m3 O3)。对照组在第1、8、15天进行腹腔注射生理盐水,第19~25天用灭菌生理盐水每天进行30 min的无菌生理盐水雾化。OVA组在第1、8、15天进行腹腔注射0.3 ml OVA致敏液,在第19~25天使用1%OVA溶液雾化。OVA+O3组采用与OVA组相同的处理方式构建哮喘模型,且在第19~25天OVA溶液雾化后2 h进行2.14 mg/m3臭氧暴露3 h,持续7 d。测定小鼠肺组织中的CGRP和SP的改变,以及肺泡灌洗液IL-4、IL-5、IL-13以及炎症细胞水平、血清总IgE和OVA-IgE的含量。观察小鼠肺部气道的病理学变化以及气道高反应性的改变。结果与OVA致敏组相比,OVA+O3组出现气道高反应性,肺组织CGRP水平和SP水平增加,气道狭窄,大量炎症细胞浸润,血清总IgE和OVA-IgE、肺泡灌洗液白细胞总数、淋巴细胞、中性粒细胞与嗜酸性粒细胞数、IL-4、IL-5和IL-13的含量升高,差异均有统计学意义(P<0.01)。结论臭氧暴露能够加重过敏性哮喘的相关症状,并且很有可能是通过诱导肺组织产生CGRP和SP来实现。

Objective To investigate the role of calcitonin gene-related peptide(CGRP)and substance P(SP)on ozone-exacerbated allergic asthma in mice.Methods A total of 24 SPF grade Balb/c mice were randomly divided into three groups,control,OVA sensitization group,OVA+ozone exposure group(OVA+2.14 mg/m3 O3).On days 1,8 and 15,mice in control group,and mice in OVA sensitization group and OVA+ozone exposure group were intraperitoneally injected with 0.3 ml normal saline and 0.3 ml OVA sensitization solution respectively.From day 19 to 25,mice in control group,OVA exposure group and OVA+ozone exposure group were exposed to aerosol inhalation of normal saline,1%OVA and 1%OVA respectively;Mice in OVA+ozone exposure group were exposed to 2.14 mg/m3 ozone for 3 hours,2 h after OVA sensitization every day.The contents of CGRP and SP in lung tissue,and IL-4,IL-5,IL-13,IgE and inflammatory cells in bronchoalveolar lavage fluid(BALF),total IgE and OVA-IgE in serum were determined.Meanwhile,pathological changes of pulmonary airway in mice were observed,and changes of airway hyperresponsiveness(AHR)were detected by the animal pulmonary function analysis system.Results Compared with OVA sensitization group,AHR,airway stenosis,inflammatory cell infiltration,significantly higher levels of CGRP and SP in lung tissue,total IgE and OVA-IgE in serum,total count of white cells,count of lymphocytes,neutrophils,eosinophil and IL-4,IL-5,IL-13,IgE in BALF were found in OVA+ozone exposure group(P<0.01).Conclusion Increased expression of CGRP and SP may be an important mechanism underlying the ozone-aggravated allergic asthma.