肺孢子虫肺炎小鼠动物模型的研究

目的建立免疫抑制昆明小鼠肺孢子虫肺炎动物模型。方法饮水中加入地塞米松（DEX）抑制小鼠免疫功能，通过对小鼠生存情况、肺组织病原学和病理学观察，判断小鼠是否诱发肺孢子虫肺炎；通过比较不同剂量DEX（2．5mg／L、5mg／L、7．5mg／L）对小鼠死亡情况、肺孢子虫感染情况的影响，确定适宜的DEX剂量。结果小鼠免疫抑制第4周查到滋养体，第7周查到包囊，第10周肺组织出现典型的间质性肺炎病理改变；DEx3个剂量组（2．5mg／L、5mg／L、7．5rag／L）均能感染肺孢子虫，但以5mg／L组感染率较高（75％），且小鼠死亡率较低（26．67％）。结论饮水中加入DEX可以建立昆明小鼠肺孢子虫肺炎动物模型，适宜剂量5mg／L。

Establishment of an immuno-suppressive mouse model of Pneumocystis pneumonia in Kunming strain of mice by using dexamethasone

The immunosuppressive mouse model of Pneumocytis pneumonia in Kunming strain of mice was attempted to establish by feeding with drinking water contaning different doses of dexamethasone (2.5 mg/L, 5 mg/L and 7.5 mg/L),and the general condition, death rate, gross observation of lungs,detection rate of Pneumocystis cysts and trophozoites in lung sections and the pathological examination of pulmonary tissues were observed in order to judge whether mice treated with dexamethasone will be liable to be infected by Pneumocystis or not. It was found that the trophozoites of Pneumocystis could be identified in the pulmaonary impression sections 4 weeks after drug use ,and the cysts of this organism demonstrated after 7 weeks with administration of drug. Ten weeks later the typical features of Pneumocystis pneumonia could be demonstrated . The optimal dose of dexamethasone to establish this mouse model was 5 mg/L with a higher infectivity rate (75%) and a lower mortality rate (26.67%)of the treated mice. It is evident that the immuno-suppressive mouse model of Pneumocystis pneumonia in Kunming strain of mice is established by using dexamethasone in drinking water.