Effects of aging on muscle fibers and collagen content of the diaphragm: a comparison with the rectus abdominis muscle.
Effects of aging on muscle fibers and collagen content of the diaphragm: a comparison with the rectus abdominis muscle.
复制标题
衰老对膈肌纤维和胶原蛋白含量的影响：与腹直肌的比较。
作者：
C. J. Rodrigues;A. J. Rodrigues Júnior;G. Bohm
研究了1、4、8、18月龄大鼠膈肌（DIA）和腹直肌（RA）肌纤维和胶原含量的年龄相关性变化。到8个月时，DIA和RA的所有肌纤维类型（I、IIa、IIb）的横截面积和胶原蛋白的数量都有所增加，之后呈抛物线曲线下降。老年DIA中I型纤维的比例增加，而RA中IIb型纤维的比例很高。老年DIA对疲劳的抵抗力增强，但以缓慢收缩为代价，而老年RA更快更强。衰老的DIA和RA肌肉显示胶原蛋白含量低，交联浓度高，导致组织粘弹性低，顺应性降低。
Age-related changes of muscle fiber and collagen content of the diaphragm (DIA) and rectus abdominis (RA) muscles were examined in rats aged 1, 4, 8 and 18 months. The cross-sectional areas of all muscle fiber types (I, IIa, IIb) and the amount of collagen in both DIA and RA increased up to the age of 8 months after which a decrease in growth following a parabolic curve was found. The older DIA showed an increase in the percentage of type I fibers while in RA there was a high percentage of type IIb fibers. The aged DIA became more resistant to fatigue but at the expense of slow contraction while older RA is faster and stronger. Aged DIA and RA muscles showed a low amount of collagen with great concentration of cross-linkings leading to a tissue with low viscoelastic properties and reduced compliance.