Brown M
Age Ageing. 1987 Jul;16(4):244-8. doi: 10.1093/ageing/16.4.244.
Skeletal muscle fibre loss and other changes were evaluated in 25 female rats aged 6-24 months. Soleus (SOL) and extensor digitorum longus (EDL) muscles were removed bilaterally. Left SOL and EDL muscles were digested in nitric acid, then, using a dissecting microscope, total fibre numbers for each muscle were obtained. Right muscles were frozen, sectioned and stained with ATPase and alkaline phosphatase to assess fibre-type distribution and capillary number. No significant change in total fibre number was seen with age in either muscle. Atrophy was common after age 12 months but was not found consistently. No reduction in capillary number was observed, even among atrophic fibres. Results suggest that atrophy and not fibre loss, per se, occurs with ageing and that atrophy is not due to capillary loss.
在25只6至24个月大的雌性大鼠中评估了骨骼肌纤维损失及其他变化。双侧切除比目鱼肌（SOL）和趾长伸肌（EDL）。将左侧的SOL和EDL肌肉用硝酸消化，然后在解剖显微镜下获得每块肌肉的总纤维数量。右侧肌肉冷冻、切片，并用ATP酶和碱性磷酸酶染色，以评估纤维类型分布和毛细血管数量。两种肌肉的总纤维数量均未随年龄出现显著变化。12个月龄后萎缩很常见，但并非始终存在。即使在萎缩纤维中也未观察到毛细血管数量减少。结果表明，衰老过程中发生的是萎缩而非纤维损失本身，且萎缩并非由毛细血管损失所致。
