过度训练雌性大鼠骨密度的变化及其机制

Research on the changes and it's mechanism of bone mass density of overtraining female rats

目的:建立过度训练大鼠模型,并研究其骨量变化及机制。方法:将225只3月龄雌性SD大鼠随机分为运动组120只和对照组105只。运动组和对照组大鼠各随机分成7组。运动组大鼠进行17周的跑台训练。动态观察体重、血红蛋白(Hb)、血清雌二醇(E2)变化作为造模监控指标;检测骨密度(BMD)、血清骨I型胶原氨基端延长肽(PINP)、骨I型胶原羧基末端肽交联(ICTP)、基质金属蛋白酶8(MMP-8)含量的变化,探讨骨量变化及其机制。结果:在持续17周的跑台训练中,体重、Hb、E2显著性降低,符合过度训练的表现;BMD降低,血清PINP变化不明显,血清ICTP显著性升高,血清MMP-8显著性升高。结论:通过17周的跑台训练成功建立了过度训练动物模型;雌激素水平下降,导致MMP-8升高,骨分解代谢增强,是过度训练导致低骨量的原因。

Objective： To establish the model of overtraining female rat and explore the changes and it＇s mechanism of bone mass. Method： A total of 225 aged 3-month female SD rats were randomly divided into training and control teams; training team of 120 rats were divided into 7 groups, the other 105 rats were divided into 7 groups also as control team. The training groups were trained on rat-treadmill for 17 weeks. The body weight, concentration of hemoglobin （Hb） and estrogen （E2） in serum were observed dymamically as modeling indicators; the changes of bone mass density （BMD） and concentration of precollege type I amino terminal propertied （PINP）, cross-linked c-telopeptide of collagen type I（ICTP） and matrix metalloproteinase 8（MMP-8） in serum were detected to probe the course of changes of bone mass and it＇s mechanism. Result： After 17-weeks training period, the training groups had significant changes in body weight, Hb and E2, which were according to the performance of overtraining; meanwhile, BMD reduced significantly, concentration of ICTP and MMP-8 in serum increased significantly and PINP had no obvious change compared to control groups at the coincident time. Conclusion： It was successful in establishing the overtraining model of female rat by 17-week treadmill training. The reduced concentration of E2 in serum could induce the increase of MMP-8 in serum, strengthen the catabolism of bone and cause the bone mass loss at last.