Department of Physiology, University of Otago, Dunedin, New Zealand.
Biogerontology. 2012 Apr;13(2):157-67. doi: 10.1007/s10522-011-9365-0. Epub 2011 Nov 3.
Sarcopenia is the age-related loss of skeletal muscle mass and strength, attributable in part to muscle fibre loss. We are currently unable to prevent fibre loss because we do not know what causes it. To provide a platform from which to better understand the causes of muscle fibre death we have quantified fibre loss in several muscles of aged C57Bl/6J mice. Comparison of muscle fibre numbers on dystrophin-immunostained transverse tissue sections at 6 months of age with those at 24 months shows a significant fibre loss in extensor digitorum longus and soleus, but not in sternomastoid or cleidomastoid muscles. The muscles of the elderly mice were mostly lighter than their younger counterparts, but fibres in the elderly muscles were of about the same cross-sectional area. This study shows that the contribution of fibre death to sarcopenia is highly variable and that there is no consistent pattern of age-related fibre loss between skeletal muscles.
肌肉减少症是与年龄相关的骨骼肌质量和力量的丧失，部分归因于肌肉纤维的丧失。我们目前无法预防纤维损失，因为我们不知道是什么导致了它。为了提供一个更好地了解肌肉纤维死亡原因的平台，我们已经量化了老年 C57Bl/6J 小鼠几种肌肉中的纤维损失。在 6 个月和 24 个月时用抗肌营养不良蛋白免疫染色的横组织切片比较肌纤维数量，显示在伸趾长肌和比目鱼肌中有明显的纤维损失，但在胸锁乳突肌或斜方肌中没有。老年小鼠的肌肉比年轻小鼠的肌肉轻得多，但老年肌肉中的纤维横截面积大致相同。这项研究表明，纤维死亡对肌肉减少症的贡献是高度可变的，并且在骨骼肌之间没有一致的与年龄相关的纤维损失模式。
