摘要
目的观察模拟航天失重状态下呼吸道感染肺炎链球菌后抗感染能力的变化，为航天医疗保障提供依据。方法建立模拟失重状态下大鼠链球菌肺炎模型，将32只健康雄性清洁级Wistar大鼠按随机数字表法分为4组：悬吊注菌组（A组）、悬吊未注菌组（B组）、未悬吊注菌组（C组）及未悬吊未注菌组（D组），每组8只，采用国内外公认成熟的尾悬吊法（身体纵轴与水平面约成30。）模拟失重状态，悬吊第4天通过气管插管法将0．4ml（细菌浓度约9．0×10^8CFU／m1）的标准肺炎链球菌菌株（ATCC6303，血清型3型，美国菌种保藏中心保存）注入肺组织，建立肺炎链球菌感染模型，对照组同时注入同等量的无菌生理盐水，仅注入1次。悬吊7d后取材，测定血常规、C反应蛋白及cDf／CD8。观察肺组织（每组均取右肺上叶）的炎症反应，并测量实验前后动物体重的变化。结果A组肺组织表面凹凸不平，呈颗粒样改变，光镜下可见较严重的肺淤血和小静脉、毛细血管充盈扩张，肺泡融合增多，肺泡间隔增厚及肺泡腔受压变形，B、C组也可见部分上述改变，但程度较轻。各组间白细胞总数未见明显差异（F=1．57，P=0．22）；A组中性粒细胞数为（2．4±0．5）×10^9／L，B组为（2．0±0．3）×10^9／L，C组为（1．7±0．4）×10^9／L，均高于D组的（1．2±0．2）×10^9／L（M值分别为0、1．0和8．5，均P〈0．05），A组与C组比较，差异有统计学意义（／Z=9．0，P=0．02）。中性粒细胞百分比A组为0．26±0．04，高于C组的0．19±0．05（u=8．5，P：0．01）；B组为0．23±0．03，C组为0．19±0．05，均高于D组的0．15±0．02（／t值分别为2．0和13．0，均P〈0．05），而B组和C组比较差异无统计学意义（u=20．0，P=0．21）；各组淋巴细胞总数比较差异无统计学意义（F=0．72，P=0．55），但A组[（6．0±0．9）×10^9／L]低于D组[（6．3±0．6）×10^9／L]；淋巴细胞百分比A组为0．66±0．08，B组为0．68±0．05，均低于D组的0．79±0．02（F=10．24，P〈0．001）。A组C反应蛋白为（11．9±2．2）g/L，明显高于D组的（1．5±0．8）g／L（M=0，P=0．001）；4组CD4／CD8＋比值无明显差别（F=1．23，P=0．32）；与其他组比较，A组体重减轻最明显，差异有统计学意义（F=122．07，P〈0．001）。结论失重状态下大鼠机体免疫功能降低，抗肺炎链球菌感染能力降低，肺部炎症反应更强，体重减轻更明显，需要给予相应的保障措施。
Objective To study the changes of anti-Streptococcus pneumonia （SP） status in rats with simulated weightlessness, and therefore to provide theoretical basis for the aerospace medicine. Methods Thirty-two healthy male Wistar rats were randomly allocated into 4 groups： group A, the tail- suspension and SP group; group B, the tail-suspension without SP group ; group C, the unsuspended but SP group; group D, the unsuspended and no SP group, with 8 rats in each. The tail-suspension method, i.e. about 30° head-down tilt, was used for the model of simulated microgravity. On day 4, 0. 4 ml of SP suspension [ ATCC6303, serotype Ⅲ （ATCC, bacteria concentration about 9. 0 ×10^9CFU/ml ）] was instilled by tracheal intubation. Sterile saline was used for the control group. The experiment was ended after 7 days of tail-suspension. Lung pathology, blood test and C-reactive protein level were studied, and the CD4＋/CD8 ratios were measured by flow cytometry. Results The lung pathological changes were much more severe in Group A as compared to those in Group B, C and D. The total number of WBC showed no significant difference among groups （ F = 1.57, P = 0. 22）. But the neutrophil number was higher in Group A [ （2. 4 ±0. 53）×10^9/L ], B [ （2. 0 ±0. 31 ）×10^9/L I and C [ （ 1.7 ±0. 40） ×10^9/L] as compared to Group D [（1.2＋0. 15） ×10^9/LI , u =0.0001,P =0.001; u=l.0,P=0.001; u =8.5,P=0.013, respectively. The percentage of neutrophils showed a similar difference. The total number of lymphocytes showed no significant difference among groups （ F = 0. 720, P = 0. 548 ）. CRP levels in the SP infection groups were significantly higher than those in the uninfected groups. The ratio of CD4/CDa＋ showed no difference among groups （ F = 1. 225, P = 0. 319 ）. Weight loss after the experiment was most severe in Group A （ F = 122. 067, P 〈 0. 001 ）. Conclusions In rats with simulated weightlessness, the anti- infective ability to Streptococcus pneumoniae was reduced, and the inflammatory response was significantly increased, but the anti-infective immunity was compromised.
出处
《中华结核和呼吸杂志》
CAS
CSCD
北大核心
2012年第7期515-519,共5页
Chinese Journal of Tuberculosis and Respiratory Diseases
基金
全军医学科学技术研究“十二五”重点项目（BWS11J051）
关键词
失重模拟
大鼠
肺炎球菌感染
Weightlessness simulation
Rats
Pneumococcal infections
