Micro-injury of the achilles tendon caused by acute exhaustive exercise in rats: Ultrastructural changes and mechanism
10.3969/j.issn.2095-4344.2990
- Author:
Shen JINBO
1
Author Information
1. Department of Physical Education, Yuncheng University
- Publication Type:Journal Article
- Keywords:
Collagen;
Exercise;
Exhaustion;
Factor;
Protein;
Rat;
Soft tissue;
Tendon
- From:
Chinese Journal of Tissue Engineering Research
2021;25(8):1190-1195
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: Studies have shown that injury and scar of the Achilles tendon in rats with terminal disease are difficult to heal, and the early treatment of Achilles tendon micro-injury caused by exhaustive exercise can avoid the accumulation of injury and prevent the occurrence of terminal disease. Therefore, it is necessary to explore the mechanism of Achilles tendon micro-injury caused by acute exhaustive exercise. OBJECTIVE: Through the comparison of the changes of ultra-structure, transforming growth factor-β1 (TGF-β1), Collagen-I, Collagen-III, matrix metalloproteinases-1 (MMP-1) and tissue inhibitors of metalloproteinase-1 (TIMP-1) mRNA and protein expression in the Achilles tendon before and after exhaustive exercise, to discuss the mechanism of Achilles tendon micro-injury caused by acute exhaustive exercise in rats. METHODS: Wistar rats were randomly divided into a control group and an exhaustive exercise group. No intervention was performed in the control group. In the exhaustive exercise group, rats were subjected to treadmill running. After exhaustive exercise, the two groups of rats were immediately killed under anesthesia. Through the observation using hematoxylin-eosin staining and transmission electronic microscopy, Achilles tendons were measured by reverse transcription-polymerase chain reaction and double antibody sandwich ABC-ELISA to show the genetic expression and protein expression of TGF-β1, Collagen-I, III, MMP-1 and TIMP-1. RESULTS AND CONCLUSION: Compared with the control group, the acute exhaustive exercise group showed the disordered arrangement of collagen fibers in Achilles tendon and the partially damaged structure of tendon cells. The mRNA and protein expressions of TGF-β1, MMP-1 and TIMP-1 were significantly higher in the exhaustive exercise group than the control group (P < 0.05), whereas the mRNA and protein expressions of Collagen-I and Collagen-III were significantly decreased (P < 0.05). These findings indicate that the over-expression of TGF-β1 results from the gradual accumulation of Achilles tendon micro-injuries caused by acute exhaustive exercise. Collagen synthesis decreases while the degradation accelerates; the tendon function is impaired as the micro-injuries continue. There is a similar variation tendency of MMP-1 and TIPM-1, which reminds an irreversible damage do not occur. Micro-injuries of the Achilles tendon caused by acute exhaustive exercise should be treated and repaired in time, avoiding excessive damage and scar repair.
