间歇负重跑台联合有氧运动对胰岛素抵抗大鼠股骨微结构及力学特性的影响

Effects of micro-structure and biomechanical properties treatment with weight-bearing treadmill running and aerobic exercise on the femur in rats

将24只雄性胰岛素抵抗SD大鼠随机分为3组:有氧运动组(AE)、有氧联合间歇负重运动组(AE-WR)和对照组(CON),研究有氧运动和间歇负重联合有氧运动对胰岛素抵抗大鼠股骨微结构及力学特性的影响。AE组进行有氧跑台运动,坡度为0°,速度为15m/min,每次持续运动40min,每周6次,持续运动8周,周日休息。AE-WR组周一、周三、周五进行间歇负重跑台运动,坡度为0°,速度为15m/min,每组运动2min,休息2min,每天运动10组;周二、周四、周六运动方案与AE组相同,持续运动8周,周日休息。CON组不施加干预。8周训练结束后,将SD大鼠断头处死,即刻将下肢解剖,取出左右股骨分别用来进行股骨微结构和生物力学特性的检测分析。Micro-CT定量分析结果显示,AE组与AE-WR组股骨的骨小梁数量(Tb.N)、骨体积分数(BV/TV)和骨密度(BMD)均显著高于CON组(P<0.05),骨小梁分离度(Tb.Sp)显著低于CON组(P<0.05)。三点弯曲实验结果显示,AE-WR组股骨的最大载荷(ML)显著高于CON组(P<0.05);与CON组对比,AE组与AE-WR组股骨的能量吸收(EAC)和刚度均显著高于CON组(P<0.05)。持续8周的有氧运动和间歇负重联合有氧运动均对胰岛素抵抗大鼠股骨的微结构和生物力学特性产生了一定的改善作用,且两种运动方式相比较而言,间歇负重联合有氧运动组的效果稍优于有氧运动组。

To evaluate the effects of two types of movement to the femur by observing the effect of micro-structure and biomechanical properties treatment with aerobic combined weight on the femur in rats,twenty-four male Sprague-Dawley rats were randomly divided into 3 groups：aerobic exercise group（AE）,aerobic weight-bearing exercise（AE-WR）,control group（CON）.AE group were trained,running on a motor-driven treadmill（Duanshi,China）at a speed of 15m/min（0°incline）,lasted about 40 min,6days/week.AE-WR group were trained,running on a motor-driven treadmill（Duanshi,China）at a speed of 15m/min（0°incline）bearing with 35%their body-weight mass added,two minutes running and two minutes intervals between each 40 minutes cycle on Monday,Tuesday and Wednesday.On Tuesday,Thursday and Saturdaymovement scheme is the same as the AE group.After trained with 8 weeks,all rats were euthanized by pentobarbital sodium,and the femur were harvested for Micro-CT and three-point test.As the results revealed by Micro-CT,compared with the CON group,the trabecular number（Tb.N）,bone mineral density（BMD）and bone volume over total volume（BV/TV）of the AE group and AE-WR group increased significantly（P〈0.05）,meanwhile the trabecular separation（Tb.Sp）decreased significantly（P〈0.05）.The three-point test showed that,the maximum loading（ML）of the AE group is significantly higher than the CON group.The stiffness（slope linear）and energy absorption（EAC）in the AE group and AE-WR group increased significantly compared with the CON group.The results suggested that both ways of weight-bearing training can improve the micro-structure and the biomechanical properties in different degrees after the 8weeks of weight-bearing training,and the effect of aerobic weight-bearing exercise group was slightly better than aerobic exercise group.