严重胸部创伤复合内毒素感染对肺泡与肺间质巨噬细胞吞噬功能的影响

Effect of severe thoracic trauma combined with endotoxin challenge on phagocytosis function of alveolar macrophages and pulmonary interstitial macrophages

目的 :观察正常大鼠肺泡与肺间质巨噬细胞吞噬功能的差异 ,比较两种细胞对严重胸部创伤、创伤复合内毒素感染的不同反应性。方法 :采用胸部撞击伤模型 ,造成动物严重胸部致伤 ;分离、纯化动物肺泡和肺间质巨噬细胞 ,检测两种细胞创伤前和创伤后 2、4、8、16和 2 4 h吞噬功能的动态变化。结果 :创伤早期 (2和 4 h)巨噬细胞吞噬功能增强 ,随后下降 ;肺泡巨噬细胞吞噬功能在创伤前后各时间点均显著强于间质巨噬细胞(P均 <0 .0 1) ;复合内毒素感染后 ,肺泡巨噬细胞吞噬功能未受影响 ,但间质巨噬细胞的吞噬能力进一步增强。结论 :肺泡和间质巨噬细胞具有功能异质性 ,而且两种细胞亚群对创伤及复合内毒素感染的反应性不同 ,提示两者在创伤后机体免疫功能紊乱中的地位不同。

Objective: To observe the difference of phagocytosis between alveolar macrophages and pulmonary interstitial macrophages, and to investigate their responses to severe thoracic trauma with or without lipopolysaccharide(LPS) challenge. Methods: A rat model of severe thoracic trauma was reproduced by thoracic impact machine. The alveolar macrophages and interstitial macrophages were isolated before injury and at 2, 4, 8, 16, 24 hours after injury respectively. The dynamic changes of these macrophage phagocytosis were tested by malachite green colorimetry. Results: Macrophage phagocytosis function was increased during the early stage after trauma (2 and 4 hours) and then decreased. The phagocytosis function of alveolar macrophages was stronger than that of interstitial macrophages in all time points before and after trauma. After challenge with LPS, no further significant effect on the alveolar macrophages was found, while LPS challenge could stimulate the phagocytosis of interstitial macrophages. Conclusion: Alveolar macrophages and pulmonary interstitial macrophages are functional heterogenous, and their response to trauma and combined with endotoxin challenge are different. The results indicate that the two subgroups of macrophages play different roles in immune function disorder after trauma.