烟雾吸入性损伤对大鼠肺泡巨噬细胞吞噬功能及炎细胞凋亡的影响

Effects of smoke inhalation injury on the phagocytic function of rat alveolar macrophage and on neutrophil apoptosis

目的 探讨烟雾吸入性损伤对大鼠肺泡巨噬细胞吞噬功能及炎细胞凋亡的影响。 方法 选用 5 4只Wistar大鼠 ,取其中 6只作为正常对照组 ,其余 4 8只制成烟雾吸入伤模型 ,作为吸入伤组。吸入伤组分别于致伤后 2、6、12、2 4h及 2、3、4、5d行支气管肺泡灌洗 ,获取肺泡巨噬细胞。观察 (1)肺泡巨噬细胞体外对鸡红细胞吞噬功能的动态变化 ;(2 )利用髓过氧化物酶 (MPO)染色法观察肺泡巨噬细胞的染色阳性率 ;(3)利用流式细胞仪观察支气管肺泡灌洗液中炎细胞凋亡的动态变化。 结果 (1)烟雾吸入伤早期 (2～ 6h)肺泡巨噬细胞吞噬鸡红细胞功能受损 ,吞噬率下降 ,12h后逐渐恢复正常。 (2 )肺泡巨噬细胞MPO染色阳性率在吸入伤后逐渐升高 ,2 4h达峰值 ,2～ 5d逐渐下降。 (3)支气管肺泡灌洗液中细胞凋亡率在 3.0 2 %～ 12 .95 %之间 ,以伤后 2 4h凋亡率最高。 结论 支气管肺泡灌洗液中炎细胞凋亡增加 ,中性粒细胞凋亡及肺泡巨噬细胞吞噬凋亡细胞参与了烟雾吸入伤大鼠恢复期肺内炎症消散的过程。

Objective To investigate the effects of smoke inhalation injury on the phagocytic function of rat alveolar macrophages and neutrophil apoptosis. Methods Wistar rats inflicted with smoke inhalation injury were employed in the study. Fifty-four Wistar rats were randomly divided into normal control(N, n=6) and inhalation injury(I, n=48) groups. Alveolar macrophages were harvested from the BALF(bronchoalveolar lavage fluid) in I group of rats at 2,6,12 and 24 postburn hours(PBHs) and on 2,3,4 and 5 postburn days(PBDs). The dynamic change in the phagocytosis of chicken erythrocytes by alveolar macrophages in vitro was observed. The positive rate of myeloperoxidase(MPO) staining of alveolar macrophages(AMs) by MPO staining method was observed, so as to indirectly reflect neutrophil apoptosis and the phagocytosis o apoptotic neutrophils by AMs. Furthermore, the dynamic change in the inflammatory cell apoptosis within BALF was monitored by flow cytometry. Results (1) he phagocytosis of chicken erythrocytes by AMs was decreased during early postburn stage(2-6 PBHs) but recovered after 12 PBHs. (2) The positive MPO staining of AMs was increased gradually after injury and reached top level at 24 PBHs, but decreased during 2-5 PBDs. (3) The apoptotic rate within BALF was around 3.02%-12.95% and rose to peak value at 24 PBHs. Conclusion There was increased apoptosis of inflammatory cells within BALF. The resolution process of inflammation after smoke inhalation injury involved neutrophil apoptosis and the phagocytosis of apoptotic neutrophils by AMs.