去卵巢骨质疏松模型大鼠L_4脊椎骨的应力松弛与蠕变

背景：去卵巢大鼠脊椎骨会发生哪些应力松弛与蠕变及时间的变化规律？目的：观察去卵巢骨质疏松对雌性大鼠承重骨黏弹性特性的影响。方法：Wistar雌性大鼠44只随机等分为对去卵巢骨质疏松动物模型组和对照组。模型组大鼠于0周摘除卵巢,14周后对大鼠L4椎骨进行应变增加速度为1%/s的应力松弛实验和应力增加速度为0.01MPa/s的蠕变实验,在7200s采集100个数据。结果与结论：大鼠L4椎骨对照组7200s应力松弛量和蠕变量大于模型组（P〈0.05）;同时大鼠L4椎骨应力松弛曲线是以对数关系变化的,蠕变曲线是以指数关系变化的。提示去卵巢骨质疏松大鼠椎骨黏弹性力学特性发生了改变。

L_4 vertebra stress relaxation and creep properties in ovariectomized rats with osteoporosis

BACKGROUND：For the prevention and treatment of osteoporosis,it is necessary to understand the relationships of the creep and stress relaxation of the spine with time in ovariectomized rats.OBJECTIVE：To observe the osteoporosis effects on the viscoelastic properties of load-bearing bone of ovariectomized female rats.METHODS：Forty-four Wistar female rats were divided into control and osteoporosis model groups.Rats in the model group were ovariectomized at 0 week.Stress relaxation trial with 1%/s strain rate and creep experiment with 0.01 MPa/s stress increasing rate.100 data were collected within 7 200 seconds.RESULTS AND CONCLUSION：The amount of stress relaxation and creep on L4 segment within 7 200 seconds was higher in the control group than the model group（P 0.05）.The stress relaxation curve changed in logarithmic manner,and the creep curve changed in exponential manner.The viscoelastic properties of ovariectomized rats with osteoporosis have changes.