多种细胞因子在哮喘大鼠发病中的作用

Effect of multiple cytokines on the pathogenesis of asthmatic rats

目的:在建立大鼠哮喘模型基础上观察细胞因子的水平变化,探讨其可能的作用机制。方法:实验于2006-09/10在锦州医学院医学实验中心完成。①实验材料:清洁级8～12周龄SD大鼠45只,雌雄各半(22和23只),体质量(200±50)g。卵白蛋白(邦定泰克生物技术有限公司);百日咳杆菌菌苗(卫生部生物制品研究所菌苗室)。②实验分组:按随机法分为3组,每组15只,雌雄各半(7或8只),为正常对照组、哮喘模型组、地塞米松组。③实验干预:模型组、地塞米松组采用卵白蛋白注射雾化吸入致敏激发法复制哮喘模型。地塞米松组同时吸入地塞米松(剂量为1mg/kg)。正常对照组用等量生理盐水替代进行腹腔注射和雾化吸入。各组在最后1次雾化后,腹主动脉取血,取上清液备用。行支气管肺泡灌洗,回收支气管肺泡灌洗液,吸取上清液备用。④实验评估:均采用酶联免疫分析法测定血清及支气管肺泡灌洗液上清液中白细胞介素4,5,10,12,13,干扰素γ水平变化。结果:45只大鼠都存活,均进入结果分析。各组大鼠血清细胞因子水平及肺泡灌洗液细胞因子水平呈现相同的统计学结果,哮喘模型组白细胞介素4,5,13明显高于正常对照组(P<0.05～0.01),白细胞介素10,12,干扰素γ明显低于正常对照组(P<0.05～0.01);地塞米松组与哮喘模型组相比,白细胞介素4,5,13降低(P<0.05～0.01),白细胞介素10,12,干扰素γ增高(P<0.05～0.01)。结论:哮喘的发病与白细胞介素4,5,10,12,13及干扰素γ等多种细胞因子有关,其中白细胞介素10的作用机制十分复杂,它与调节性T细胞可能在哮喘的发病中起着重要作用,用Th亚群功能失衡理论不能完全解释哮喘的发生。

AIM： To observe the changes of cytokine and explore its mechanisms of action in rat models of asthma. METHODS： The experiment was conducted at the Medical Experimental Center of Jinzhou Medical College from September to October 2006. （1） Totally 45 SD, clean grade rats, （22 females and 23 males） aged 8-12 weeks and with a body mass of （200±50） g were selected. Ovalbumin and pertussis bacillus vaccine were purchased from Bangding Taike Biotechnology Co., Ltd. and Vaccine Room, institute of Biological Products Ministry of Health, respectively. （2）The rats were randomly divided into 3 groups, namely normal control group, asthmatic model group and dexamethasone group. Fifteen rats （7 females and 8 males） were included in each group. （3）The asthmatic models were established by challenging the rats with nebulized inhalations of ovalbumin （OVA） in asthmatic model group and dexamethasone group. Dexamethasone （1 mg/kg） was administered simultaneously also by nebulized inhalation in the dexamethasone group. The same dose of saline solution was used in the normal control group to replace intraperitoneal injection and nebulized inhalation. Abdominal aorta blood samples were obtained from each rat of all groups after the last nebulized inhalation and serum was stored. Every group was given bronchoalveolar lavage and the supernatant of bronchoalveolar lavage fluid （BALF） was prepared and stored. （4）The serum and BALF levels of interleukin-4, 5, 10, 12 and 13 and interferon gamma were detected by enzyme-linked immunoassay （ELISA） in all samples from every group. RESULTS： Totally 45 rats were involved in the result analysis. The cytokine levels in serum and BALF displayed a same result without statistical significance. Levels of interleukin-4, 5 and 13 in the asthmatic model group were obviously higher than those in the normal control group（P 〈 0.05-0.01 ）. Levels of interleukin-10 and 12 and interferon gamma in the asthmatic model group were markedly lower than those in the normal control group （P 〈 0.05-0.01 ）. Levels of interleukin-4, 5 and 13 were decreased （P〈 0.05-0.01 ） and interleukin-10 and 12 and interferon gamma were raised in the dexamethasone group as compared to the asthmatic model group（P 〈 0.05-0.01 ）. CONCLUSION： Pathogenesis of asthma is associated with multi-cytokines such as interleukin-4, 5, 10, 12 and 13. Mechanisms of action are quite complicated specially for interleukin-10. This cytokine could be playing an extremely important role in the etiology of asthma basically by its action on regulatory T cells. Application of the off-balance theory in T helper cell subsets cannot explain completely the development of asthma.