ABSTRACT
BACKGROUND:Delayed onset muscle soreness is closely related to skeletal muscle micro-injury, but the exact mechanism of skeletal muscle micro-injury is not yet clear. OBJECTIVE:To observe the histomorphological and ultrastructure changes of skeletal muscle micro-injury models induced by eccentric exercise. METHODS: Forty male Sprague-Dawley rats were randomly divided into quiet control group, immediately after exercise group, post-exercise 24 hours group, post-exercise 48 hours group and post-exercise 72 hours group. In the latter four groups, the rats were subjected to intermittent running on the-16° slope at a speed of 16 m/min: 5 minutes movement, 2 minutes rest and totaly 120 minutes. Rats in the latter four groups were observed immediately, at 24, 48, 72 hours after exercise. RESULTS AND CONCLUSION:After eccentric exercise, the morphology and ultrastructure of rat’s skeletal muscle were both changed to different extents, and Desmin and Vimentin were dyed off for anti-desmin antibody staining at varying degrees. It indicates that one-time eccentric exercise can cause delayed skeletal muscle micro-injury.