脉冲电磁场对大鼠骨量和骨微结构的改善作用

Improvement of pulsed electromagnetic fields on bone mass and microstructure in rats

目的 研究脉冲电磁场(PEMF)刺激下大鼠骨量和骨微结构的变化,阐明PEMF对大鼠骨骼的改善作用。方法 将16只12周龄的SD大鼠随机分为两组(每组8只),不施加PEMF刺激的大鼠为正常组,施加PEMF刺激的大鼠为PEMF组。将PEMF组大鼠放入PEMF加载装置线圈的中央接受6周的PEMF刺激(强度为2 mT,频率为15 Hz),每日6 h;对照组SD大鼠同样放入线圈但不进行磁场刺激。在实验过程中连续观察并记录大鼠的体质量和进食量。通过旷场实验监测大鼠垂直或水平行为活动次数,使用Micro-CT扫描大鼠股骨干骺端小梁骨和皮质骨,并分析股骨骨量和骨微结构的相关参数,包括骨密度(BMD)、骨体积分数(BV/TV)、骨小梁厚度(Tb.Th)、骨小梁数量(Tb.N)、骨小梁分离度(Tb.Sp)和皮质骨厚度(Ct.Th)。结果 施加PEMF刺激的实验过程中,正常组和PEMF组大鼠的体质量和进食量无显著差异(P>0.05)。旷场实验结果表明PEMF刺激对大鼠垂直或水平行为活动度无显著影响(P>0.05)。Micro-CT分析结果揭示,PEMF组大鼠的BV/TV、BMD、Tb.N、Tb.Th和Ct.Th均显著大于正常组(P<0.01),Tb.Sp显著小于正常组(P<0.01)。结论 PEMF刺激在不影响大鼠进食、体质量及自由活动度的情况下,能显著改善大鼠骨量及骨微结构,对于骨骼发育具有明显改善作用。

Objective To investigate the changes of bone mass and microstructure in rats exposed to pulsed electromagnetic fields(PEMF),and to clarify the effects of PEMF on bone improvement in rats.Methods Sixteen 12-week-old SD rats were randomly divided into two groups,with 8 rats in each group.The rats without PEMF stimulation were in the normal group,and those with PEMF stimulation were in the PEMF group.Rats in the PEMF group were placed in the center of the coils of the device to receive PEMF stimulation(2 mT,15 Hz)with 6 h/d for 6 weeks.Rats in the control group were also placed in the coils without PEMF stimulation.The body mass and food intake of rats were observed and recorded continuously during the experiment.The number of vertical or horizontal behavioral activities of rats was monitored by open field test.Micro-CT was used to scan trabecular and cortical bone of femoral metaphysis in rats,and relevant parameters of femoral bone mass and microstructure were analyzed,including bone mineral density(BMD),bone volume per total volume(BV/TV),trabecular thickness(Tb.Th),trabecular number(Tb.N),trabecular separation(Tb.Sp)and cortical thickness(Ct.Th).Results No significant difference in body mass and food intake was observed between the normal group and PEMF group during the experiment(P>0.05).The results of open field test showed that PEMF stimulation exerted no significant effect on the vertical or horizontal behavioral activities of rats(P>0.05).Micro-CT analysis revealed that BV/TV,BMD,Tb.N,Tb.Th and Ct.Th of PEMF group were significantly higher than those of normal group(P<0.01),and Tb.Sp was significantly lower than that of normal group(P<0.01).Conclusion PEMF stimulation can significantly improve the bone mass and microstructure of rats without affecting the food intake,body mass and locomotor activity,and has a significant effect on bone development.