Vincent R, Chang L Y, Slot J W, Crapo J D
Department of Medicine, Duke University Medical Center, Durham, North Carolina 17710.
Am J Physiol. 1994 Oct;267(4 Pt 1):L475-81. doi: 10.1152/ajplung.1994.267.4.L475.
We have analyzed the magnitude and uniformity of the expression of manganese superoxide dismutase (Mn SOD) protein in alveolar type II cells of rats exposed to hyperoxia using quantitative colloidal gold immunocytochemistry and morphometric techniques. Sprague-Dawley rats were exposed continuously to normal air or to 85% oxygen for 7 and 14 days. The lungs were fixed by intratracheal instillation of a paraformaldehyde-glutaraldehyde fixative. Lung samples were dehydrated in ethanol and embedded in LR-White. Thin sections for electron microscopy were labeled with anti-rat Mn SOD rabbit antiserum followed by protein-A gold. The labeling density (gold particles/micron 2) over subcellular compartments was determined, and relative organelle volumes were measured using a random point overlay. The results confirm that alveolar type II cells are a locus of Mn SOD response in the lungs of hyperoxic rats and contribute to this response through a combination of changes: an increase of Mn SOD concentration in the mitochondrial matrix, an increase of mitochondrial volume per cell, and type II cell hyperplasia.
我们运用定量胶体金免疫细胞化学和形态计量学技术，分析了暴露于高氧环境下的大鼠肺泡Ⅱ型细胞中锰超氧化物歧化酶（Mn SOD）蛋白表达的量及均匀性。将Sprague-Dawley大鼠连续暴露于正常空气或85%氧气环境中7天和14天。通过气管内注入多聚甲醛-戊二醛固定剂对肺进行固定。肺样本在乙醇中脱水并包埋于LR-White中。用于电子显微镜检查的薄切片先用抗大鼠Mn SOD兔抗血清标记，然后用蛋白A金标记。测定亚细胞区室的标记密度（金颗粒数/微米²），并使用随机点覆盖法测量相对细胞器体积。结果证实，肺泡Ⅱ型细胞是高氧大鼠肺中Mn SOD反应的一个位点，并通过多种变化共同促成这种反应：线粒体基质中Mn SOD浓度增加、每个细胞中线粒体体积增加以及Ⅱ型细胞增生。
