糖皮质激素对肺炎支原体肺炎大鼠肺组织的病理观察

目的观察地塞米松对肺炎支原体肺炎（MPP）大鼠肺组织病理学的影响,为临床合理应用糖皮质激素治疗MPP提供理论依据。方法 95只SD大鼠随机分为4组：阿奇霉素组（n=25）、地塞米松组（n=25）、阿奇霉素＋地塞米松组（n=25）和对照组（n=20）。各组大鼠均予肺炎支原体（MP）菌液（1×106CFU.mL-1）缓慢滴入大鼠鼻腔,100μL.d-1,共4 d。各组均在MP最后1次接种后第2天开始给予干预,阿奇霉素组皮下注射阿奇霉素10 mg.kg-1.d-1,地塞米松组腹腔注射地塞米松磷酸钠0.5 mg.kg-1.d-1,阿奇霉素＋地塞米松组给予阿奇霉素10 mg.kg-1.d-1和地塞米松磷酸钠0.5 mg.kg-1.d-1,对照组给予相同体积生理盐水。治疗后第1、3、5、8和10天后处死大鼠取肺组织行病理学检查,并对肺组织炎症浸润程度进行评分。结果①治疗后第1天,各组均可见不同程度的肺实质及血管周围淋巴细胞浸润。第5天,对照组和地塞米松组仍可见细支气管及血管周围较多淋巴细胞浸润;阿奇霉素组和阿奇霉素＋地塞米松组支气管周围淋巴细胞浸润减轻。第10天,对照组和地塞米松组可见肺组织及血管周围较多淋巴细胞浸润;阿奇霉素组和阿奇霉素＋地塞米松组可见终末支气管周围少许淋巴细胞浸润。②各组肺组织病理学评分显示,对照组治疗后不同时点,肺组织病理学评分均维持在较高水平,显著高于阿奇霉素组和阿奇霉素＋地塞米松组;地塞米松组治疗后不同时点,肺组织病理学评分呈显著增高趋势,提示炎症浸润程度的加重;阿奇霉素组和阿奇霉素＋地塞米松组在治疗后第5、8和10天均呈下降趋势,其中阿奇霉素＋地塞米松组低于阿奇霉素组。结论在阿奇霉素基础上加用地塞米松可明显减轻MPP大鼠肺组织炎症。

Study of effect of dexamethasone on lung histopathological changes with mycoplasma pneumoniae pneumonia in rats

Objective To observe the effect of dexamethasone on histopathologic change of lung tissue of rats with mycoploasma pnermoniae pneumonia and the influence of dexamethasone on lung tissue in rats.Methods Ninety-five rats were randomly divided into four groups：azithromycin group（n=25）,dexamethasone group（n=25）,azithromycin＋dexamethasone group（n=25） and control group（n=20） by dropping mycoplasma pnermoniae bactieria liquid to nose of rats on day 0,1,2,and 3.Four groups recieved interventions on the 4th day： azithromycin（10 mg·kg-1） daily for azithromycin group,dexamethasone（0.5 mg·kg-1） for dexamethasone group,azithromycin（10 mg·kg-1） SQ and dexamethasone（0.5 mg·kg-1） IP once daily for azithromycin＋dexamethasone group and sterile 0.9% saline for control group.Five rats for intervention groups and 4 for control group were sacrificed on day 1,3,5,8 and 10.Lung tissues were processed and fixed,histopathologic score（HPS） was determined by a pathologist who was unaware of the grouping information.Results ①On day 1 of interventions,lymphocytes infiltration at different degrees was seen in lung tissue or around blood vessels in all groups.On day 5,more lymphocytes infiltration around bronchioli and blood vessels was observed in control and dexamethasone groups,but reduced lymphocytes filtration was seen in azithromycin and azithromycin＋dexamethasone groups.On day 10,the observation kept the same for control and dexamethasone groups,but further reduced lymphocytes infiltration was seen only around terminal bronchiolis in the other two groups.②Histopathologic score（HPS） showed that at different time points after treatment in control group,HPS of lung tissue maintained at higher level,significantly higher than those in azithromycin and azithromycin＋dexamathasone groups.In dexamethasone group,HPS of lung tissue at different time points showed an increasing trend that suggested increased inflammatory infiltration.In azithromycin and azithromycin＋dexamethasone groups,5,8,10 days after treatment inflammatory infiltration was decreased,and azithromycin＋dexamethasone group was better than azithromycin group.Conclusions After 3 days treatment,combination therapy of azithromycin and dexamethasone significantly reduced lung HPS compared with the control group,dexamethasone group and the group using azithromycin alone.