游泳运动对大鼠创伤性关节挛缩的影响及机制.

BACKGROUND: Early exercise treatment is the main prevention way for traumatic joint contracture and is also a research focus. Swimming may be a potential intervention for joint contracture due to the special physical properties of water. OBJECTIVE: To explore the effects of swimming on the development of joint contracture in a rat model and study its mechanisms. METHODS: Twenty-four Sprague-Dawley rats were randomly divided into a blank control group (n=8) and a joint contracture group (n=16). After the surgical operation of knee joint contracture rat models, the joint contracture group was randomly subdivided into a surgical control group (n=8) and a swimming treatment group (n=8). Swimming started in the swimming treatment group in the second week after surgery and lasted for a total of 5 weeks. At the 6th week after surgery, the body mass, knee joint range of motion, and quadriceps diameter were tested, and the diameter/body mass index was calculated. Hematoxylin-eosin staining was performed to detect the pathological changes in the knee joint capsule and quadriceps muscle, and Masson staining was used to observe fibrotic changes in the knee joint capsule. Furthermore, the protein expression of transforming growth factor β1 and type I collagen in the knee joint capsule was quantified by immunohistochemical assay and western blot was performed to detect the protein expression of MuRF1 in the quadriceps femoris. RESULTS AND CONCLUSION: Compared with the blank control group, the knee range of motion decreased in the surgical control and swimming treatment groups (P < 0.01), and knee extension deficit and arthrogenic extension deficit were significantly increased (P < 0.01), the diameter of the quadriceps muscle was decreased (P < 0.01), the joint capsule showed significant fibrosis, the quadriceps muscle was atrophied, and the diameter/body mass index was decreased (P < 0.01). Compared with the surgical control group, the swimming treatment group showed a significant increase in knee joint range of motion and quadriceps diameter (P < 0.01), and significant improvement in joint capsule fibrosis and quadriceps atrophy. Compared with the blank control group, collagen fiber content and expression of transforming growth factor β1 and type I collagen were increased in the joint capsule of rats in both the surgical control group and the swimming treatment group (P < 0.01). Compared with the surgical control group, collagen fiber content and expression of transforming growth factor β1 and type I collagen protein in the joint capsule were decreased in the swimming treatment group. Compared with the blank control group, the expression of MuRF1 protein in the quadriceps muscle of rats in the surgical control group and the swimming treatment group was increased (P < 0.05). Compared with the surgical control group, the expression of MuRF1 protein in the quadriceps muscle of rats in the swimming treatment group was decreased (P < 0.05). To conclude, early swimming intervention reduces transforming growth factor β1 and type I collagen expression in the joint capsule of traumatic joint contracture rats, decreases MuRF1 expression in the quadriceps muscle, and increases joint range of motion and quadriceps diameter, thereby inhibiting the development of joint contracture. [ABSTRACT FROM AUTHOR]