Sarcomere length during post-natal growth of mammalian muscle fibres.
Sarcomere length during post-natal growth of mammalian muscle fibres.
复制标题
哺乳动物肌肉纤维出生后生长期间的肌节长度。
作者：
G. Goldspink
测量了不同年龄小鼠肱二头肌肌纤维的肌节长度、A丝和1丝及其重叠百分比。肢体处于完全伸展位置时的肌节长度从新生动物的2.3 µ增加到成年动物的2.8 µ。这种增加是由于长丝的重叠百分比降低，而不是由于长丝长度的任何变化。在所有年龄段，纤维末端的肌节都比肌肉中间的肌节短。当肌肉被拉伸超过其静止长度时，年轻肌肉中只有大约中间60%的肌节长度增加。长度/张力图获得年轻和老年肌肉和这些图的形状的差异可以解释为由于非功能性的终端肌节的年轻肌肉。年轻肌肉产生的最大张力被发现在初始肌肉长度比它们在最大肢体伸展时的长度大约10%时达到。成人肌肉在最大肢体伸展时产生最大张力。
The length of the sarcomeres, the A- and the 1-filaments and their percentage overlap were measured in the fibres of the biceps brachii muscle from mice of different ages. The sarcomere length with the limb in the fully extended position was found to increase from 2.3 µ in the newborn animal to 2.8 µ in the adult. This increase was due to a decrease in the percentage overlap of the filaments and not to any change in the filament lengths. The sarcomeres at the ends of the fibres were found to be shorter than those in the middle of the muscle, at all ages. When the muscles were stretched beyond their resting length, only about the middle 60 % of the sarcomeres in the young muscles increased in length. Length/tension plots were obtained for young and old muscles and the difference in the shape of these plots could be explained as being due to the non-functional terminal sarcomeres of the young muscles. The maximum tension developed by the young muscles was found to be attained at an initial muscle length about 10 % greater than their length at maximum limb extension. The adult muscles developed maximum tension at their length at maximum limb extension.