低应力环境对大鼠股骨的骨密度和几何形态学的影响

切断6周大鼠的坐骨神经,使其右后肢处于低应力环境中。测量股骨不同部位的骨密度和几何形态学参数。结果发现,低应力环境下大鼠股骨的直径、皮质骨面积和骨矿密度的增加明显受抑制。但不同部位的骨密度对低应力环境的敏感性不同,表现为早期富于松质骨的股骨干骺端骨密度增加幅度的受抑,接着是富于皮质骨的骨干部的骨密度增长幅度的降低。几何形态学结果提示,早期干骺端骨密度增长幅度的降低是由于骨吸收增强,而皮质骨的骨量和尺寸的增长受抑制是骨膜骨形成持续减少的结果。

Effect of Low Stress Environment on Bone Density and Geome-morphology of Rat Femur

6-week old rats were subjected to sciatic nerve resection and the right hindlimbs were then under a low stress environment.Bone mineral density(BMD) of different regions and geome-morphological parameters of femurs were measured.The results showed that the increase in the diameter,subperiosteal area and bone mineral density of femurs were suppressed obviously under low stress environment.But the sensitivity of BMD of different regions of the femur to the low stress environment was different.The suppression of the increase in femoral BMD was composed of an early impairment in the gain of BMD at the femoral metaphysis,which is rich in trabecular bone,and a sustained reduction in the gain of BMD at the femoral diaphysis,which is rich in cortical bone.The results of geome-morphology suggested that the early reduction in the increase of BMD at the metaphysis was due to an enhancement of bone resorption,whereas the suppression of gain in cortical bone mass and size is the result of a sustained reduction of periosteal bone formation.