目的 研究肺炎支原体(MP)感染后不同时期大鼠气道的反应状态.方法 将45只SD雄性大鼠随机分为4组:空白对照组15只,MP感染急性期组、恢复期组、痊愈期组各10只.采用滴鼻法对实验大鼠进行MP感染,并以1%OVA溶液对其进行雾化吸入诱导大鼠喘息发作,实验后处死动物,留取支气管肺泡灌洗液进行MP-PCR检测及IL-4和IFN-γ含量测定,留取肺组织制成切片,光镜下观察肺组织形态改变.结果 以MP培养液滴鼻大鼠,行MP-PCR检测,其总阳性率为92%;随着时间的推移,大鼠肺内炎症程度逐渐减轻,经1% OVA溶液雾化吸入后,各期MP感染大鼠均出现类似支气管哮喘发作的表现;支气管肺泡灌洗液中IL-4和IFN-γ含量先升高,后逐渐降低;但IL-4升高的程度重,持续时间长,故呈现Th2细胞优势,且在恢复期尤为明显.结论 MP感染后,大鼠气道存在慢性炎症及高反应状态,出现Th1/ Th2细胞功能的失衡,且持续时间较长,以恢复期时最为明显.%Objective It is to research the rat's airway reactivity in the different time after Mycoplasma pneumoniae ( MP ) infections. Methods Forty-five male SD rats were randomly divided into four groups: normal control group had 15 ones, MP infection acute phase group, convalescence group and recovery group had 10 ones respectively. The rats were infected with MP by the intranasal method, and were given 1% OVA by aerosol inhalation to induce asthma. After experiment the animals were killed and their bronchus alveolarlavage fluid ( BALF ) was left to do determination by MP - PCR, and to detect the contents of IL -4 and IFN - γ. The lung tissue was collection to make sections to observe the changes of lung histomorphometry under light microscope. Results The total positive rate by MP - PCR was 92% in the rats, which were used intranasal method with MP culture fluid; as time went by, the inflammatory changes in the rats'lung tissues was gradually relieved. After inhaled by 1%OVA, the rats in different time all appeared the symptoms like the attacks of bronchial asthma. The contents of IL -4 and IFN - γ were all firstly increased, and then gradually decreased; but the degree of IL -4 content was increased significantly, and the content had long duration, this feature showed the Th2 cellular superiority, and had particularly evident in the recovery stage. Conclusion The airway of the rats infected by MP has chronic inflammatory and hyper responsiveness, the function of Th1/Th2 cellular immunity was in the state of imbalanced. This stage has long duration, and is most obvious in the recovery stage.
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