骨量及骨代谢中胰岛素生长因子1、转化生长因子β和白细胞介素6在长期递增负荷运动状态下的变化

Changes in bone mass,insulin-like growth factor 1,transforming growth factor β and interleukin 6 during long-term progressively increasing load training

背景:研究表明,合理的适量运动能够促进骨量,相反过量运动会影响骨量的蓄积,但负荷过量的运动对骨代谢的影响作用机制目前仍不清楚。目的:探讨长期递增负荷运动对骨量的影响效应,以及对骨代谢的影响作用机制。方法:将SD大鼠分别进行4,9,11,13,15,17周的递增负荷运动,并设置对照组,以放射免疫分析法测定各组大鼠雌二醇水平,以酶联免疫法测定各组血清胰岛素生长因子1,转化生长因子β及白细胞介素6的浓度,以双能X射线骨密度仪测定各组骨密度水平。结果与结论:和同期对照组相比,胰岛素生长因子1和转化生长因子β在运动后9和17周显著降低(P<0.05),转化生长因子β在运动第4周显著升高(P<0.05),白细胞介素6在运动第9,15,17周均显著升高(P<0.05)。雌二醇水平在运动第13,15和17周降低(P<0.05或P<0.01),全身骨密度值在运动第15,17周显著降低(P<0.01)。结果证实,长期递增负荷运动导致大鼠机体骨代谢发生改变,由骨形成占优势过渡为骨吸收占优势,最终出现骨密度值降低,骨代谢平衡向破骨方向倾斜的重要致因与过量运动所造成的性腺轴功能受抑,雌二醇水平降低有关。

BACKGROUND：Studies have demonstrated that a reasonable amount of regular exercise can increase bone mass and excessive exercise would influence the accumulation of bone mass.However,the precise mechanism underlying the effect of excessive exercise on bone metabolism remains poorly understood.OBJECTIVE：To investigate the effect of long-term progressively increasing load training on bone mass and bone metabolism.METHODES：Sprague-Dawley rats were given 4,9,11,13,15 and 17 weeks of progressively increasing load exercise.A control group was set.Estradiol level in each group was measured by radioimmunoassay and serum level of insulin-like growth factor 1（IGF-1）,transforming growth factor β（TGF-β）and interleukin 6（IL-6）was determined by enzyme-linked immunosorbent assay.Bone mineral density in each group was determined by dual energy x-ray absorptiometry.RESULTS AND CONCLUSION：Compared with the control group,IGF-1 and TGF-β levels were significantly decreased after 9 and 17 weeks of training（P 0.05）,TGF-β level was significantly increased after 4 weeks of training（P 0.05）,IL-6 level was significantly increased after 9,15,and 17 weeks of training（P 0.05）,estradiol level was significantly decreased after 13,15 and 17 weeks of training（P 0.05 or P 0.01）,and bone mineral density was significantly decreased after 15 and 17 weeks of training（P 0.01）.Results showed that long-term progressively increasing load training resulted in bone metabolism changes from bone formation to bone absorption superiority and finally leaded to decrease in bone mineral density.The reasons of bone resorption superiority may be related to inhibition of sex gland axis and lower serum estradiol level.