[Effects of high-load exercise induced skeletal muscle injury on autophagy ultrastructure and Beclin1 and LC3-II / I in rats].

OBJECTIVE

To investigate the effects of high-load eccentric exercise on the ultrastructure of autophagy and the autophagy-related proteins Beclin1 and LC3II / I in rats.

METHODS

Forty-eight SD male rats were randomly divided into control group (C, =8) and high-load eccentric exercise group (E, =40) after adaptive training. Group E was run downhill for 90 minutes on the running platform, and soleus muscles were collected at 0, 12, 24, 48 and 72 hours after exercise. Transmission electron microscopy was used to observe the ultrastructural changes of skeletal muscle autophagosomes. Western blot was used to detect the expressions of Beclin1 and LC3II / I protein. Immunofluorescence was used to observe the localization and content of LC3.

RESULTS

The number of soleus muscle autophagosomes in group E was increased at 0, 12 and 24 hours after exercise, and LC3 autophagic fluorescence was significantly increased (＜0.01), while autophagic fluorescence at 48 hours after exercise was still increased significantly (＜0.05). Beclin1 and LC3II / I expression levels were increased after high-load centrifugal intervention (＜0.05), and were peaked at 12 h～24 h after exercise (＜0.01), and fully recovered at 72 h after exercise.

CONCLUSION

High-load eccentric exercise can induce ultrastructural changes in skeletal muscle autophagy and increase the expression of autophagy protein. The peak value appears at 12 hours after exercise. The above may be one of the reasons for the decline in skeletal muscle function caused by sports injury.