SKELETAL-MUSCLE ATROPHY IN OLD RATS - DIFFERENTIAL CHANGES IN THE 3 FIBER TYPES
SKELETAL-MUSCLE ATROPHY IN OLD RATS - DIFFERENTIAL CHANGES IN THE 3 FIBER TYPES
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DOI：
10.1016/0047-6374(91)90131-i
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发表时间：
1991-10-01
影响因子：
5.3
通讯作者：
YOUNG, JC
中科院分区：
文献类型：
--
作者：
HOLLOSZY, JO;CHEN, M;YOUNG, JC
本研究旨在重新评估衰老对大鼠骨骼肌质量的影响以及对不同类型骨骼肌中线粒体和糖酵解酶水平的影响。研究发现，雄性大鼠的一些肌肉会随着年龄的增长而萎缩，而另一些则不会。肌肉萎缩似乎发生在负重肌肉中，在IIb型纤维比例较高的肌肉中最为明显。没有萎缩的肌肉是非负重的，包括外轮匝肌(主要是IIb型纤维)和长内收肌(主要是I型纤维)。28~30个月龄大鼠足底肌肌纤维横截面积比9~10个月龄大鼠小约30%，说明老年组大鼠足底肌重减轻约30%完全是由于肌纤维萎缩所致。老年大鼠足底IIa型纤维比例减少，I型纤维比例增加。老年大鼠比目鱼肌的呼吸能力(主要是I型纤维)和股外侧肌浅、白色(IIb)和深红色(主要是IIa型)部分的糖酵解能力降低。我们的结果提供了证据，表明衰老对大鼠三种类型的骨骼肌纤维以及对负重和非负重肌肉的影响是不同的。
This study was undertaken to reevaluate the effects of ageing on skeletal muscle mass and on mitochondrial and glycolytic enzyme levels in the different types of skeletal muscle in rats. It was found that.some muscles atrophy with ageing, while others do not, in male rats. Atrophy appears to occur in weight-bearing muscles, and is most marked in those with a high proportion of type IIb fibers. The muscles that did not atrophy are non-weight-bearing, and include the epitrochlearis (predominantly type IIb fibers) and the adductor longus (predominantly type I fibers). The average cross-sectional area of muscle fibers in the plantaris muscles of 28-30-month-old rats was approximately 30% smaller than that of 9-1 0-month-old animals, providing evidence that the appproximately 30% lower weight of the plantaris in the old group was entirely due to fiber atrophy. The proportion of type IIa fibers was decreased and the proportion of type I fibers was increased in the plantaris of the old rats. The respiratory capacity of the soleus muscle (predominantly type I fibers), and the glycolytic capacity of the superficial, white (type IIb) and deep, red (predominantly type IIa) portions of the vastus lateralis, were reduced in the old rats. Our results provide evidence that ageing has differential effects on the three types of skeletal muscle fiber, and on weight-bearing and non-weight-bearing muscles, in the rat.