去卵巢骨质疏松模型大鼠L4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0.01 MPa/s的蠕变实验，在7 200 s采集100个数据。结果与结论：大鼠L4椎骨对照组7 200 s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。

L4 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.