限制运动对大鼠股骨、胫骨物理性状、生物力学指标及骨形成蛋白2表达的影响

Effects of activity restriction on the physical characteristics,biomechanical properties and bone morphogenetic protein 2 expression of femur and tibia in rats

目的:本研究比较了限制运动4wk大鼠和正常对照组大鼠下肢股骨、胫骨物理性状包括湿质量,灰质量,骨矿含量,骨密度,生物力学指标以及骨形成蛋白2表达量的变化,目的在于找出限制运动对大鼠下肢骨生长有哪些不良影响.方法:采用腿-尾固定法制造大鼠限制运动的模型,用DPX双能X线骨密度仪测量大鼠左侧下肢骨骨矿含量和骨密度,用WD万能材料试验机进行股骨3点弯曲试验,测算出股骨的破坏强度,破坏载荷,破坏时能量吸收和刚度系数等生物力学指标,采用免疫组化染色及灰度比较的方法比较骨形成蛋白2表达的变化.结果:限制运动4wk后,大鼠股骨、胫骨的湿质量,灰质量,骨矿含量,骨密度,生物力学指标与正常对照组比较存在下降,并且与骨形成密切相关的骨形成蛋白2的表达也下降.结论:限制运动对大鼠下肢骨(股骨、胫骨)的生长产生了负面影响,表现在下肢骨物理性状的变化及骨形成蛋白表达的抑制等方面.

AIM： To investigate the effects of activity restriction on the physical characteristics, biomechanical properties and bone morphogenetic protein 2 （BMP2） expression of femur and tibia in rats. METHODS： Totally 32 male SD rats were randomly divided into experimental group and control group. In the experimental group 16 rats＇ posterior limbs were fixed together with tails to restrain their activity for 4 weeks. Thereafter the 32 rats were executed to weigh the wet weight, gray weight, and detect the bone mineral content （ BMC）, bone mineral density （BMD） by dual energy X-ray absorptiometry （DPX） and some important biomeehanical parameters of femur and tibia and BMP2 expression by immunohistochemistry in experimental group and control group. RESULTS： The wet weight, gray weight, BMC and BMD of femur and tibia were all reduced significantly in the experimental group and expression of BMP2 was also decreased markedly in experimental group as compared with control group. CONCLUSION： Activity restriction has negative effects on bone morphogenesis of posterior limbs and BMP2 may be an important factor to mediate the process.