论文部分内容阅读
目的 研究间断性 45°头高位对抗措施 (intermittent+4 5°head- up- tilt,IHU T)对尾吊大鼠承重骨的影响 .方法 SD雄性大鼠 2 0只 ,按体质量配对后随机分为 :对照组 (C,7只 ) ,悬吊组 (S,6只 ) ,头高位组 (H,7只 ) .在尾吊大鼠模型模拟失重的基础上 ,H组大鼠每日给予 6 h IHUT.利用物理测量和三点弯曲等实验 ,观察了 4wk IHUT对尾吊大鼠股骨生长、生物力学特性的影响 .结果 S,H组大鼠股骨质量、灰分、直径和密度均较 C组大鼠显著下降 (P<0 .0 1或 P<0 .0 5 ) ;与 S组比较 ,H组大鼠的直径 (P<0 .0 5 )和密度 (P<0 .0 1)显著改善 ,质量和灰分有增加趋势 .与 C组相比 ,S组大鼠股骨的强度和刚度显著降低 (P<0 .0 1) ;H组最大载荷和刚性系数显著降低 (P<0 .0 5 ) ,韧性系数显著升高 (P<0 .0 1) .与 S组大鼠相比 ,H组大鼠弹性载荷显著提高 (P<0 .0 5 ) ,最大载荷、刚性系数和挠度载荷比值有提高趋势 .结论 IHUT对尾吊大鼠的承重骨的生长及力学特性有一定改善作用
Objective To investigate the effect of intermittent +4 5 ° head-up-tilt (IHU T) on the weight-bearing bone in tail-suspended rats.Methods Twenty SD male rats were randomized The rats were divided into four groups: control group (C 7), suspension group (S 6) and head high group (H 7) Given 6 h IHUT.The effects of 4wk IHUT on femoral growth and biomechanical properties of tail-suspended rats were observed by physical measurements and three-point bending test.Results The femoral mass, ash, diameter and density of rats in groups S and H were significantly (P <0.01 or P <0.05). Compared with group S, the diameter and the density of rats in group C (P <0. 05) and density (P <0.01), and the maximum load and rigidity of H group were significantly lower than those of C group (P <0. 01) (P <0.01) .Compared with S group, the elastic load of rats in group H was significantly increased (P <0.05), the maximum load, stiffness coefficient and Deflection load ratio tends to increase. Conclusion IHUT have some effect on the growth and to improve the mechanical properties of load bearing bone of the tail suspended rats