Department of Pediatrics and Medicine, McMaster University, 1200 Main Street West, Hamilton, Ontario, Canada.
J Gerontol A Biol Sci Med Sci. 2010 Feb;65(2):119-28. doi: 10.1093/gerona/glp179. Epub 2009 Dec 3.
The purpose of this study was to determine whether ultrastructural changes in intramyocellular lipid (IMCL) and mitochondria occur with aging. Muscle samples were analyzed from 24 young and 20 old, equally active, individuals for IMCL and mitochondria quantity and size as well as their association. Old men had larger IMCL droplets than all other groups in the total muscle area. Old individuals showed higher IMCL content in the subsarcolemmal area. Young participants had a greater number of mitochondria compared with old participants in both fiber regions and greater enzyme activities of cytochrome c oxidase and citrate synthase. The fraction of IMCL touching mitochondria was lowest in old women in the total area and in old men in the subsarcolemmal region. In summary, older adults have larger IMCL droplets, fewer mitochondria, and a lower proportion of IMCL in contact with mitochondria. These factors likely contribute to age-related reductions in mitochondrial function and lipid metabolism.
本研究旨在确定肌细胞内脂质（IMCL）和线粒体的超微结构变化是否随年龄增长而发生。对 24 名年轻和 20 名年老、同样活跃的个体的肌肉样本进行了分析，以评估 IMCL 和线粒体的数量和大小及其相关性。老年人的肌纤维总面积中的 IMCL 液滴比其他所有组都大。老年人的肌小节下区域的 IMCL 含量更高。与老年人相比，年轻人在两个纤维区域的线粒体数量更多，细胞色素 c 氧化酶和柠檬酸合酶的酶活性也更高。在总区域，老年女性和肌小节下区域，老年男性的 IMCL 与线粒体接触的比例最低。总之，老年人的 IMCL 液滴更大，线粒体更少，与线粒体接触的 IMCL 比例也更低。这些因素可能导致与年龄相关的线粒体功能和脂质代谢的减少。
