McKiernan Susan H, Bua Entela, McGorray Jennifer, Aiken Judd
Department of Animal Health and Biomedical Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA.
FASEB J. 2004 Mar;18(3):580-1. doi: 10.1096/fj.03-0667fje. Epub 2004 Jan 20.
The purpose of this work was to determine the effect of early-onset calorie restriction on sarcopenia in the aging rat. Ad libitum (AL) fed animals were examined at 5, 18, 21, and 36 months of age. Calorie-restricted (CR) rats, 40% restricted since 4 months of age, were examined at 21 and 36 months of age. By 36 months, vastus lateralis, rectus femoris and soleus muscles, from AL-fed rats, had significant muscle mass and fiber loss, and reduced muscle cross-sectional area. Mean fiber diameter decreased with age in the vastus lateralis and rectus femoris but not the soleus of AL-fed rats. The number of Type I fibers significantly increased in the vastus lateralis with age. Calorie restriction did not prevent muscle mass loss with age; however, it significantly reduced muscle mass loss between 21 and 36 months of age compared with age-matched AL cohorts. Calorie restriction prevented fiber loss with age, and this conservation of fiber number reduced muscle mass loss with age.
这项工作的目的是确定早期开始的热量限制对衰老大鼠肌肉减少症的影响。对自由采食（AL）的动物在5、18、21和36月龄时进行检查。自4月龄起热量限制（CR）40%的大鼠在21和36月龄时进行检查。到36月龄时，自由采食大鼠的股外侧肌、股直肌和比目鱼肌出现了显著的肌肉质量和纤维损失，且肌肉横截面积减小。在自由采食大鼠的股外侧肌和股直肌中，平均纤维直径随年龄增长而减小，但比目鱼肌没有。股外侧肌中I型纤维的数量随年龄显著增加。热量限制并不能防止肌肉质量随年龄下降；然而，与年龄匹配的自由采食组相比，它在21至36月龄时显著减少了肌肉质量的损失。热量限制防止了纤维随年龄减少，这种纤维数量的保留减少了肌肉质量随年龄的损失。
