不同应力水平的持续运动对生长期大鼠骨矿含量和力学特性的影响

Effects of Different Impact Training on Mineralization and Mechanical Properties of Growing Rats' Bone

为了探讨不同应力水平的运动对生长期大鼠长骨生长发育的影响。将24只4周龄雌性SD大鼠随机分为3组,即对照组,游泳运动组和跑台运动组,每组8只,游泳运动组和跑台运动组分别进行为期9周,每周5次,每次60 min的游泳和跑台运动。运动结束后取后肢胫骨进行骨矿含量和三点弯曲实验。游泳运动组各项骨矿含量指标皆高于对照组,仅骨灰度密度具有显著性差异。跑台运动组各项骨矿含量指标除骨灰度外都显著高于对照组。生物力学指标中,游泳运动组的弹性载荷非常显著的高于对照组,显著高于跑台运动组,跑台运动组弹性载荷显著高于对照组,最大载荷和弹性载荷非常显著地高于对照组。结果提示,两种应力水平的运动都能够提高胫骨的骨矿含量,跑台运动的作用较强。两种运动对骨的生物力学特性皆有一定的影响,但作用有所不同,跑台运动对骨的抗变形能力的提高高于游泳运动,而游泳运动的对骨的抗断裂能力的提高高于跑台运动。

In order to research the effects of different impact exercises on growing rats＇ bone growth, 24 female SD rats （4 weeks old ） are randomly assigned to a running group （Run n= 8）, a swimming group （Swim, n= 8） and a control group （con, n= 8）. During a 9 weeks training session （60 mins/day, 5 days/week）, the Run rats are trained at progressively increasing running speeds （ 10-20 m/rain）, and weights attached to the tail of the Swim rats from the 4th week and then on. Wet weight, dry weight, ash weight, bone apparent density, bone ash density of the Run rats＇ tibiae are all significantly higher than those in the Con group, but only bone ash density of the Swim rats is higher than that of the Con rats. Except maximum load, all the data of tibiae＇ mechanical properties of both of the training groups are all higher than those in the Con group, and the Run group＇ s maximum deformation and bending deformation and elastic load of the Swim group are much higher than the Con group＇s （P〈 0.001）. In summary, different impact exercises and training have the different effects on the growing bone in different ways and the influences of running training is stronger than that of the swimming training.