Abstract:

BACKGROUND: Collagen is the main protein component of tendon tissue. Metalloproteinases are a large family of enzymes capable of degrading all of the tendon matrix components.
OBJECTIVE: To investigate the effects of 12-week treadmill running on content of collagen and the expression of procollagen I, matrix metalloproteinases-1 (MMP-1) and tissue inhibitors of metalloproteinase-1 of rat Achilles tendon.
METHODS: A total of 20 male Sprague-Dawley rats were randomly assigned to control and exercise groups. At 1 week, exercise was performed for 20 minutes daily, at the increased speed from 12 m/min to 20 m/min. The treadmill speed was kept at 20 m/min. At 2 weeks, the gradient was 5%, and time was 30 minutes. At 3-12 weeks, the gradient was 10%, and the time was 40 minutes, for totall 12 weeks. In control group, the animals were fed normally.
RESULTS AND CONCLUSION: 24 hours after the last exercise, the rat Achilles tendon was obtained. Compared with control group, the expression of procollagen Iα1, MMP-1 and its inhibitor 1 mRNA was significantly increased (P < 0.05 or P < 0.01) in the exercise group, and the hydroxyproline content was increased (P > 0.05). These results show that long-term treadmill running can increase the synthesis and degradation of collagen in achilles tendon.