运动后针刺腓肠肌干预肥胖大鼠肌腱退行性病变

Effects of post-exercise gastrocnemius needling on Achilles tendon degeneration in obese rats

背景:运动后腓肠肌张力升高是导致退行性病变的主要原因,超重者的发病风险更高,通过针刺腓肠肌可以降低运动后腓肠肌张力。目的:观察通过针刺运动后力学生长因子和组织蛋白表达变化,从而探讨针刺腓肠肌对跟腱退行性病变风险的影响。方法:32只12周龄雄性SD大鼠给予高脂饲料喂养4周建立肥胖大鼠模型,体质量(500.27±29.11) g,随机分为4组:空白对照组、运动组、针刺组及运动针刺组。运动强度为60 min 60%的最大摄氧量(15.6 m/min)以-16°进行离心运动,每周运动6 d持续4周;每次运动结束后分别对针刺组和运动针刺组进行针刺干预,针刺位置为腓肠肌中部,每次针刺时间为5 min。第5周对大鼠跟腱及腓肠肌进行取材,苏木精-伊红染色观察跟腱组织结构变化;免疫荧光染色检测跟腱内胶原蛋白以及相关细胞因子表达;Western-blot分析腓肠肌转化生长因子β1表达。实验方案已经获得北京体育大学实验动物伦理委员会批准。结果与结论:①运动与运动针刺组大鼠跟腱组织出现纤维排列紊乱的现象;②运动组大鼠腓肠肌中转化生长因子β1蛋白表达显著高于其他3组(P <0.05),运动针刺组显著高于对照和针刺组(P <0.05);③运动组大鼠跟腱中Ⅰ型胶原蛋白水平显著低于其他3组(P <0.05);Ⅲ型胶原蛋白水平显著高于其他3组(P <0.05);运动针刺组Ⅲ型胶原蛋白水平高于针刺和对照组(P <0.05);④运动组大鼠跟腱中基质金属蛋白酶1表达显著低于其他3组(P <0.05);基质金属蛋白酶13表达显著高于其他3组(P <0.05);⑤运动组大鼠跟腱中转化生长因子β1表达显著高于其他3组(P <0.05),运动针刺组显著高于针刺和对照组(P <0.05);⑥胰岛素样生长因子1表达各组间比较没有显著差异;⑦结果说明,运动后针刺腓肠肌可以降低肥胖大鼠跟腱退行性病变风险。

BACKGROUND:Post-exercise gastrocnemius tension increase is the main cause of degeneration,and overweight people are more susceptible.The gastrocnemius needling treatment has been considered as an effective way to reduce post-exercise muscle tension.OBJECTIVE:To study the effect of post-exercise gastrocnemius needling treatment on the risk of Achilles tendon degeneration by observing the changes in the expression of mechanical growth factors and tissue proteins after needling.METHODS:Thirty-two 12-week-old male Sprague-Dawley rats were fed with high fat diet for 4 weeks to establish obese rats with a body weight of(500.27±29.11)g.All rat models were randomly divided into blank control group,exercise group,needling group and post-exercise needling group.Eccentric running at-16°was performed,and the exercise intensity was set at 60%of the maximum oxygen uptake(15.6 m/min)for 60 minutes.The exercise was performed 6 days per week for 4 continuous weeks.Needling treatment was performed in the needling group and the post-exercise needling group at the end of each exercise.The needle position was in the middle of the gastrocnemius muscle,and the needling time was 5 minutes.Achilles tendon and gastrocnemius of rats were harvested followed by histological analysis in the 5 th week.Hematoxylin-eosin staining was used to observe the structural changes of Achilles tendon;immunofluorescence staining was used to detect the expression of collagen and related cytokines in the Achilles tendon;western blot assay was used to detect transforming growth factorβ1 expression in the gastrocnemius.The study protocol was approved by the Experimental Animal Ethics Committee of Beijing Sport University.RESULTS AND CONCLUSION:The collagen fibers of the Achilles tendon were disordered in the exercise and post-exercise needling groups.The expression of transforming growth factorβ1 in the gastrocnemius was significantly higher in the exercise group than the other three groups(P<0.05),and was significantly higher in the post-exercise needling group than the blank control and needling groups(P<0.05).The expression of type I collagen in the Achilles tendon was significantly lower in the exercise group than in the other three groups(P<0.05).The expression of type III collagen was significantly higher in the exercise group than in the other three groups(P<0.05),and significantly higher in the post-exercise needling group than the needling and blank control groups(P<0.05).The expression of matrix metalloproteinase 1 in the Achilles tendon was significantly lower in the exercise group than the other three groups(P<0.05),whereas the expression of matrix metalloproteinase 13 in the Achilles tendon was significantly higher in the exercise group than the other three groups(P<0.05).The expression of transforming growth factorβ1 in the Achilles tendon was significantly higher in the exercise group than the other three groups(P<0.05),and was significantly higher in the post-exercise needling group than the needling and control groups(P<0.05).There was no significant difference in insulin-like growth factor 1 expression among the four groups.To conclude,post-exercise gastrocnemius needling can reduce the risk of Achilles tendon degeneration in obese rats.