Abstract:

 Objective　To explore the effects of stress on Ⅰ and Ⅲ collagen expression in the repaired conjunction between tendon and bone after acute rupture of rabbit supraspinatus tendon.   Methods　18 adult male New Zealand white rabbits were selected in this study. Two of them were taken as the controls randomly. Another 16 animals were randomly divided into two groups: stress stimulation group (group A, n=8) and no stimulation group (group B, n=8). 2 weeks after operation of tendon rupture, animals of group A were trained, while of group B were normally feed. After 2, 4, 6 and 8 weeks ,respectively, 2 rabbits at each time in each group were put to death, and prepared the specimens for detecting the expression of Ⅰ and Ⅲ collagens. Results　Collagen fibers appeared in repaired tissue for each group at the second week of the operation, with no significant difference; however, collagen expression was more strong in group A than that in group B, especially for Ⅲ collagen at the 4 weeks after operation; at the 6 weeks after operation, Ⅰ and Ⅲ collagens stained more strong and wide, followed by orderly arranged collagen fibers, compared with that of previous time points, furthermore, well-arranged and stained uniformly Ⅰ type collagen fibers appeared in A group at the 8 week. Conclusions　Stress stimulation is favorable for promoting collagen synthesis of the repaired tendon-bone interface, which will contribute to the recovery of damaged rotator cuff.

Key words: Rabbit supraspinatus tendon!Tendon-bone repair!Stress stimulation!Ⅰand Ⅲ collagen