肺泡巨噬细胞凋亡在老年多器官功能衰竭肺启动中作用的研究

目的探讨肺泡巨噬细胞(AM)凋亡在老年多器官功能衰竭(MOF)肺启动中的可能机制。方法选择SD大鼠40只,随机分为油酸+脂多糖组20只和对照组20只。应用油酸-内毒素序贯打击,复制以肺功能障碍为首发的MOF模型,分别在造模6、12、24 h后处死2组大鼠各5只,通过支气管肺泡灌洗和细胞贴壁的方法获取AM,用碘化丙啶染色流式细胞仪测定AM凋亡率。结果造模后6、12、24 h,油酸+脂多糖组大鼠AM的多器官功能障碍综合征发生率、凋亡率和游离钙含量逐渐升高,线粒体膜电位逐渐变小(P<0.01);而对照组各时间点AM的凋亡率、游离钙含量及线粒体膜电位无明显变化(P>0.05)。与对照组比较,油酸+脂多糖组造模后各时间点多器官功能障碍综合征发生率、AM的凋亡率和游离钙含量均明显升高(P<0.01),线粒体膜电位明显降低(P<0.01)。结论 AM凋亡率逐渐增加严重影响了其功能的发挥,可能是MOF发生的重要原因。AM细胞内游离钙含量逐渐升高、线粒体膜电位逐渐变小,是诱导老年大鼠AM凋亡增加的重要机制。

Role of pulmonary alveolar macrophage apoptosis in lung initiation of elderly-rats with multiple organ failure

Objective To study the role of pulmonary alveolar macrophage apoptosis in lung initiation of elderly rats with multiple organ failure(MOF).Methods Forty SD rats were randomly divided into oleic acid(OA) -Hipopolysaeeharide(LPS) group and control group(20 in each group). An elderly rat MOF model was induced by OA and endotoxin to reproduce pulmonary dysfunction. Five rats in each group were killed at 6,12,24 h respectively after the model was established. Alveolar macrophages(AM) were obtained by bronchial pulmonary alveolar lavage and cell adherent culture.Apoptosis of AM was detected by flow cytometry with iodinated propidium staining. Results The incidence of MOF,the apoptotic rate of AM,and the free calcium level were significantly higher while the mitochondrial menbrane potential was significantly lower in OA+LPS group than in control group at 6,12,24 h after the model was established(P<0.01).However,no significant difference was found in the incidence of MOF,the apoptotic rate of AM and the free calcium level in control group at 6,12,24 h after the model was established(PX).05).Conclusion Increased apoptotic rate of AM significantly affects the function of AM in elderly rats with MOF, which may be the important factor for MOF.Elevated free calcium level and decreased mitochondrial menbrane potential are the importan mechanism underlying the increased apoptosis of AM in elderly rats.