呼吸机相关性肺炎大鼠肺组织β-防御素-3的表达  

Role of beta-defensin-3 in lung tissue in a rat model of ventilator-associated pneumonia

作　　者：桂平[1] 武庆平[1] 姚尚龙[1] 李建蓉[2] 李永平[2] 

机构地区：[1]华中科技大学同济医学院附属协和医院麻醉科,武汉市430022 [2]华中科技大学同济医学院病原生物系,武汉市430022

出　　处：《中华麻醉学杂志》2009年第4期308-310,共3页Chinese Journal of Anesthesiology

基　　金：基金项目：国家自然科学基金资助项目（30571787）

摘　　要：目的观察呼吸机相关性肺炎大鼠肺组织β-防御素-3（BD-3）的表达，探讨呼吸机相关性肺炎的发病机制。方法清洁级雄性SD大鼠20只，体重240～290g，随机分为2组（n=10）：非呼吸机相关性肺炎组（N组）和呼吸机相关性肺炎组（V组）。两组均经口气管插管，N组气管内注入10^10 cfu／ml耐甲氧西林金黄色葡萄球菌菌液0．2ml；V组机械通气4h时气管内注入等容量耐甲氧西林金黄色葡萄球菌菌液，注入菌液后拔出气管导管。于注入菌液后48h时处死大鼠，取肺组织，计算肺湿重占体重百分比，行秭组织肉眼下和镜下的病理学评分，测定肺组织细菌计数，记录菌血症的发生情况，免疫组化法测定肺组织BD-3的表达水平。结果与N组比较，V组肺湿重占体重百分比、肺组织镜下病理学评分、肺组织细菌计数和菌血症发生率升高，肺组织BD-3表达下调（P〈0．01）。结论大鼠呼吸机相关性肺炎的发病机制与肺组织BD-3的表达下调有关。Objective To investigate the role of beta-defensin-3 （BD-3） in lung tissue in a rat model of ventilator-associated pneumonia. Methods Twenty pathogen-free male SD rats weighing 240-290 g were randomly divided into 2 groups （n = 10 each）： non-ventilator-associated pneumonia group （group N） and wentilatorassociated pneumonia group （group V）. The animals were anesthetized with intraperitoneal （IP） 20% urethane 1.3 g/kg. Oral tracheal intubation was performed under direct vision. In group N the animals kept spontaneous breathing. MRSA suspension （10^10 cfa/ml） 0.2 ml was introduced into bronchus immediately after tracheal intubation. The animals were then extubated. In group V the animals were mechanically ventilated （VT 6 ml/kg, RR 88 bpm, PEEP 5 cm H2 O, FiO2 21% ） for 4 h. MRSA suspension （10^10 cfu/ml） 0.2 ml was introduced into bronchus at the end of 4 h mechanical ventilation. The animals were killed at 48 h after inoculation in both groups. The lungs were removed for microscopic examination of pathologic changes which were scored. Wet lung weight/body weight ratio （WW/BW） was measured. Lung bacterial counts and spleen culture were performed. The expression of BD-3 in lung tissue was detected by immuno-histochcmical staining. Results WW/BW, lung pathology scores, lung bacterial counts and the incidence of bacteremia were significantly higher in group V than in group N, while BD-3 expression in lung tissue was significantly lower in group V than in group N. Conclusion The pathogencsis of ventilator-associated pneumonia is related to the down-regulation of BD-3 expression in rat lung tissue.

关 键 词：呼吸 人工 肺炎 细菌性 Β防御素 

分 类 号：R563.1[医药卫生—呼吸系统] R135.2[医药卫生—内科学]