Regional stiffening with aging in tibialis anterior tendons of mice occurs independent of changes in collagen fibril morphology.
Regional stiffening with aging in tibialis anterior tendons of mice occurs independent of changes in collagen fibril morphology.
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DOI：
10.1152/japplphysiol.00460.2011
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发表时间：
2011-10
影响因子：
3.3
通讯作者：
Lauren K. Wood;E. Arruda;S. Brooks
中科院分区：
文献类型：
--
作者：
Lauren K. Wood;E. Arruda;S. Brooks
肌腱退化和断裂的发生率随着年龄的增长而增加。这种风险增加的机制仍然未知，但可能是由于肌腱机械性能和结构与年龄相关的变化而出现。我们的目的是确定衰老对肌腱机械性能和胶原原纤维形态的影响。沿着成年（8至12个月大）和老年（28至30个月大）小鼠的胫骨前肌腱（TA）肌腱的长度测定区域机械特性和胶原纤维特征。沿着肌腱的所有区域的切线模量在老年时都会增加，但与肌肉相邻的近端区域的增加明显大于肌腱的其余部分。在最大肌腱应变（799 ± 157 vs. 1,419 ± 91 MPa）和生理相关应变（377 ± 137 vs. 798 ± 104 MPa）下，总体端到端模量随着年龄的增长而增加。尽管从成年到老年，肌腱的机械性能发生了巨大的变化，但在所有检查的肌腱区域中，胶原原纤维的形态和堆积分数仍然相对恒定。由于肌腱特性受到外部负荷环境的影响，我们还研究了衰老对 TA 肌肉收缩特性的影响。不同年龄组之间的最大等长力没有差异。我们得出的结论是，TA 肌腱在整个生命周期中以区域依赖性方式变硬，但机械性能的变化并不伴随胶原纤维形态或 TA 肌肉产生力的能力的相应变化。
The incidence of tendon degeneration and rupture increases with advancing age. The mechanisms underlying this increased risk remain unknown but may arise because of age-related changes in tendon mechanical properties and structure. Our purpose was to determine the effect of aging on tendon mechanical properties and collagen fibril morphology. Regional mechanical properties and collagen fibril characteristics were determined along the length of tibialis anterior (TA) tendons from adult (8- to 12-mo-old) and old (28- to 30-mo-old) mice. Tangent modulus of all regions along the tendons increased in old age, but the increase was substantially greater in the proximal region adjacent to the muscle than in the rest of the tendon. Overall end-to-end modulus increased with old age at maximum tendon strain (799 ± 157 vs. 1,419 ± 91 MPa) and at physiologically relevant strain (377 ± 137 vs. 798 ± 104 MPa). Despite the dramatic changes in tendon mechanical properties from adulthood to old age, collagen fibril morphology and packing fraction remained relatively constant in all tendon regions examined. Since tendon properties are influenced by their external loading environment, we also examined the effect of aging on TA muscle contractile properties. Maximum isometric force did not differ between the age groups. We conclude that TA tendons stiffen in a region-dependent manner throughout the life span, but the changes in mechanical properties are not accompanied by corresponding changes in collagen fibril morphology or force-generating capacity of the TA muscle.