Gosker H R, Hesselink M K C, Duimel H, Ward K A, Schols A M W J
Dept of Respiratory Medicine, Maastricht University, Nutrition and Toxicology Research Institute Maastricht, PO Box 616, 6200 MD Maastricht, The Netherlands.
Eur Respir J. 2007 Jul;30(1):73-9. doi: 10.1183/09031936.00146906. Epub 2007 Apr 11.
Skeletal muscle dysfunction is a well-recognised hallmark of chronic obstructive pulmonary disease (COPD) leading to exercise intolerance. The vastus lateralis of COPD patients is characterised by reduced mitochondrial enzyme activity; however, this is not the case in the tibialis anterior. It is, however, unclear whether the compromised oxidative capacity in the vastus is due to reduced mitochondrial volume density. Muscle biopsies were obtained from the vastus lateralis of six COPD patients and four healthy age-matched controls, and from the tibialis anterior of another six COPD patients and six controls. Mitochondrial number, fractional area and morphometry, as well as Z-line width (as a surrogate marker of fibre type), were analysed using transmission electron microscopy. Mitochondrial number (0.34 versus 0.63 n.microm(-2)) and fractional area (1.95 versus 4.25%) were reduced in the vastus of COPD patients compared with controls. Despite a reduced mitochondrial number (0.65 versus 0.88 n.microm(-2)), the mitochondrial fractional area was maintained in the tibialis of COPD patients compared with controls. It can be concluded that the reduced mitochondrial fractional area is likely to contribute to the decreased oxidative capacity in the vastus of chronic obstructive pulmonary disease patients, whereas the maintained mitochondrial fractional area in the tibialis may explain the normal oxidative capacity.
骨骼肌功能障碍是慢性阻塞性肺疾病（COPD）的一个公认特征，可导致运动不耐受。COPD患者的股外侧肌表现为线粒体酶活性降低；然而，胫前肌并非如此。然而，尚不清楚股肌氧化能力受损是否是由于线粒体体积密度降低所致。从6例COPD患者和4例年龄匹配的健康对照者的股外侧肌，以及另外6例COPD患者和6例对照者的胫前肌获取肌肉活检样本。使用透射电子显微镜分析线粒体数量、分数面积和形态学，以及Z线宽度（作为纤维类型的替代标志物）。与对照组相比，COPD患者股肌的线粒体数量（0.34对0.63个/平方微米）和分数面积（1.95%对4.25%）降低。尽管线粒体数量减少（0.65对0.88个/平方微米），但与对照组相比，COPD患者胫前肌的线粒体分数面积保持不变。可以得出结论，线粒体分数面积降低可能导致慢性阻塞性肺疾病患者股肌氧化能力下降，而胫前肌线粒体分数面积保持不变可能解释了其正常的氧化能力。
