PM_(10)颗粒物致大鼠肺炎过程中肺组织元素变化的研究

Change of elemental distributions in lung tissue of SD pneumonia mouse caused by PM_(10)

应用两级核孔滤膜的空气采样器采集了上海市区PM10 颗粒物。用质子激发X荧光(PIXE)分析了其元素含量。以SD大鼠为实验对象 ,隔日气管灌注PM10 进行染毒 ,对照用生理盐水 ;1个月后处死大鼠 ,提取支气管灌洗液并分析一些金属结合的蛋白质含量 ;观察肺组织病理改变及应用扫描质子微探针 (SPM)研究染毒组与对照组肺组织元素分布的变化。结果显示染了毒的大鼠肺具有肺炎的特征 ;其Ca与Zn的浓度明显低于对照组 ,而Fe则明显增高 ;在提取的支气管灌洗液中金属结合的蛋白质含量明显提高。由于SPM已观察到肺中不可溶的铁颗粒 ,所以增高的Fe元素可能是由于颗粒带入。Ca ,Zn元素的降低则可能是由于机体炎症生化过程所引起的 ,这也许使周围组织中不可溶的的Zn ,Ca转换成可溶性化合物而导致组织中的Zn ,Ca的流出。

PM 10 was collected by a stacked filter air sampler. The elemental contents were analyzed by proton induced X-ray emission (PIXE). The PM 10 solution was instilled every other day to SD mouse' s lung for one month. The sterile physiological saline was used as the control. One month later, histopathology of the lung tissue was studied and the elemental distributions were analyzed by Scanning Proton Microprobe (SPM). The particle instilled mouse' s lungs showed measurable inflammation, and the contents of metal binding protein (albumin etc.) in BALF were significantly higher than those of controls. The Ca and Zn contents in tissues were significantly lower than those of controls, while Fe content of PM 10 instilled mice were significantly higher than that of controls. The increased Fe content in pneumonic tissue was duo to the unsoluble Fe compounds (from PM 10 ) remaining in lung tissue which were observed by SPM. The decreased Zn and Ca contents in pneumonic tissue were duo to the progress of pneumonia. The unsoluble Zn and Ca in lung tissue may be extracted by some enzymes and then changed to soluble in the progress of pneumonia. It is suggested that the Zn and Ca efflux from lung tissue may be a way of damaging lung.