Department of Anatomy, Cell Biology, Physiology and Biophysics, State University of Campinas, SP, Brazil.
Connect Tissue Res. 2009;50(5):279-84.
The role of physical activity in affecting the composition of extracellular matrix and mechanical properties of tendons has been well studied, but little is known about the role of passive stretching. The purpose of this study was to test the hypothesis that stimulation by passive stretching may change the composition and mechanical properties of tendons. Three-month-old Wistar rats were divided into three groups: the control, animals were not submitted to stretching procedures; groups that had their calcaneal tendons manually stretched three or five times a week, for 21 days. Afterward, the calcaneal tendons were removed and assayed for hydroxyproline content and biomechanical test. The hydroxyproline content in the stretched groups was higher, suggesting that more collagen was present in the tendons of these groups. These tendons also showed higher values of maximum stress and modulus of elasticity or Young's modulus. These results indicate that stretching leads to alterations in the synthesis of the extracellular matrix components and in the mechanical properties of tendons.
运动在影响细胞外基质组成和肌腱机械性能方面的作用已经得到了很好的研究，但对于被动拉伸的作用知之甚少。本研究旨在检验被动拉伸刺激可能改变肌腱组成和机械性能的假设。将 3 月龄 Wistar 大鼠分为三组：对照组，动物未进行拉伸操作；实验组每周手动拉伸跟腱 3 或 5 次，共 21 天。之后取出跟腱，检测羟脯氨酸含量和生物力学试验。拉伸组的羟脯氨酸含量较高，提示这些组的肌腱中存在更多的胶原蛋白。这些肌腱的最大应力和弹性模量或杨氏模量值也更高。这些结果表明拉伸导致细胞外基质成分的合成和肌腱机械性能发生改变。
