不同强度跑台运动对大鼠骨成分变化的影响

Effects of different intensities of treadmill running on bone composition in rats

目的 探讨不同强度跑台运动对大鼠胫骨干骺端皮质骨和松质骨成分变化的影响.方法 将24只雌性SD大鼠随机分为4组（n=6）：低强度组、中等强度组、高强度组和自由活动组,前3组SD大鼠按照不同运动强度跑步方案（分别为15 m/min、0°坡度,20 m/min、5°坡度,25 m/min、10°坡度）进行8周训练（每周5d,1 h/d）,自由活动组作为对照组.8周后分别取各组大鼠胫骨左侧干骺端皮质骨和松质骨,应用拉曼光谱检测并分析各组的矿物质/基质比值、碳酸盐/磷酸盐比值及结晶度等. 结果 骨组织中矿物质/基质比值：中等强度组皮质骨平均为4.883±0.128,松质骨平均为4.216±0.213,均显著高于自由活动组（4.113±0.132、3.773±0.122）;高强度组松质骨平均为3.222±0.329,显著低于自由活动组,差异均有统计学意义（P＜0.05）.骨组织中碳酸盐/磷酸盐比值：中等强度组松质骨平均为0.166±0.013,显著低于自由活动组（0.177±0.011）;高强度组皮质骨平均为0.195±0.012,松质骨平均为0.187±0.010,均显著高于自由活动组（0.183±0.014、0.177±0.011）,差异均有统计学意义（P＜0.05）.高强度组皮质骨和松质骨骨组织结晶度平均分别为0.052 1±0.001 2和0.052 2±0.001 7,,均显著高于其他3组,差异有统计学意义（P＜0.05）. 结论 中等强度跑台运动能提高骨组织的矿化和转换,增强骨的质量;高强度运动会降低骨的矿化,降低骨的质量.

Objective To evaluate the effects of different intensities of treadmill running on changes in tibial bone composition in a rat model.Methods A total of 24 female Wistar rats were randomly assigned into 4 even groups （n =6） of free movement （FM）,low-intensity running （LR）,medium-intensity running （MR）,and high-intensity running （HR）.Rats in LR,MR,and HR groups underwent treadmill running with respective intensities （15 m/min and a 0° gradient,20 m/min and a 5° gradient,25 m/min and a 10° gradient） for 8 weeks （1 h/d and 5 d/week）.FM group were taken as controls.The cortical and trabecular bone at the left tibial metaphysis was harvested after 8 weeks in each group for Raman spectroscopy to analyze mineral-matrix ratio,carbonate-phosphate ratio and crystallinity.Results In MR group,the mean mineral-matrix ratio was 4.883 ± 0.128 for cortical bone and 4.216 ±0.213 for trabecular bone,both significantly higher than those in FM group （4.113 ±0.132 and 3.773 ±0.122） （P 〈 0.05）.The mean mineral-matrix ratio was 3.222 ± 0.329 for trabecular bone in HR group,significantly lower than that in FM group （P 〈 0.05）.In MR group,the mean carbonate-phosphate ratio was 0.166 ± 0.013 for trabecular bone,significantly lower than that in FM group （0.177 ± 0.011） （P 〈 0.05）.In HR group,the mean carbonate-phosphate ratio was 0.195 ± 0.012 for cortical bone and 0.187 ± 0.010 for trabecular bone,both significantly higher than those in FM group （0.183 ± 0.014 and 0.177 ± 0.011） （P 〈 0.05）.In HR group,the mean crystallinity was 0.0521 ± 0.0012 for cortical bone and 0.0522 ± 0.0017 for trabecular bone,both significantly higher than those in the other 3 groups （P 〈 0.05）.Conclusions Running with medium intensity may increase bone mineralization and turnover,thus enhancing bone quality.However,running with high intensity may decrease bone mineralization and thus bone quality.