Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
Anat Rec (Hoboken). 2013 Oct;296(10):1546-51. doi: 10.1002/ar.22759. Epub 2013 Aug 12.
A relationship between compromised muscles and other tissues has been demonstrated in mdx mouse, an animal model studied for understanding of Duchenne muscular dystrophy. The hypothesis is that changes in the calcaneal tendon of mdx mice occur previous to the onset of rigorous and most marked episodes of muscle degeneration, which start suddenly after 21 days of life. Thus, this study aimed to identify possible alterations in the calcaneal tendon of mdx mouse at 21 days of age. Control and mdx tendons were submitted to mechanical tensile testing, quantification of hydroxyproline, and staining with toluidine blue and picrosirius red. Hydroxyproline content was similar between mdx and control groups. The control tendon presented higher mechanical strength (load, stress, and elastic modulus) and its morphological analysis showed a larger number of round fibroblasts, nuclei with well-decondensed chromatin, and slightly metachromatic well-stained cytoplasmic material, different from that observed in mdx tendons. The results suggest that the absence of dystrophin in mdx mouse can provoke directly or indirectly alterations in the mechanical properties and morphology of the calcaneal tendon.
在研究杜氏肌营养不良症的动物模型 mdx 小鼠中，已经证明了肌肉和其他组织之间的关系。该假说认为，mdx 小鼠跟腱的变化发生在肌肉退化的严重和最明显阶段之前，这些变化在出生后 21 天突然开始。因此，本研究旨在确定 mdx 小鼠在 21 天时跟腱的可能变化。对对照和 mdx 跟腱进行机械拉伸测试、羟脯氨酸定量和甲苯胺蓝和苦味酸红染色。羟脯氨酸含量在 mdx 和对照组之间相似。对照跟腱具有更高的机械强度（载荷、应力和弹性模量），其形态分析显示出更多的圆形成纤维细胞、具有良好凝聚染色质的核和略带异染的染色良好的细胞质物质，与 mdx 跟腱观察到的不同。结果表明，mdx 小鼠中肌营养不良蛋白的缺失可能直接或间接地引起跟腱的机械性能和形态改变。
