Effect of sinusoidal electromagnetic field on bone mineral density and histomorphometry of rats at different time points / 中国医学科学院学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of 50 Hz 0.1 mT sinusoidal electromagnetic field at different time points on bone mineral density(BMD)and histomorphometry in rats.</p><p><b>METHODS</b>Totally 50 6-week-old female SD rats were equally randomized into 5 groups control group,45-minute group,90-minute group,180-minute group,and 270-minute group. Except for the control group,the other four groups were given magnetic intervention in the 50-Hz 0.1-mT sinusoidal electromagnetic field for 45 minutes,90 minutes,180 minutes,or 270 minutes,respectively,on a daily basis. After 8 weeks,the total body BMD,femur BMD,and vertebral BMD were measured by dual-energy X-ray absorptiometry. The left tibia and the fifth lumbar vertebrae were separated for bone tissue static and dynamic analyses.</p><p><b>RESULTS</b>Compared with control group,the 90-minute group and the 180-minute group had significantly different total body BMD(P<0.01,P<0.05),while no such significant difference was seen in the 45-minute group and 270-minute group (P>0.05). The femur,vertebral BMD,serum biochemical markers,and the static parameters of the fifth lumbar vertebrae tissue showed significant differences in the 90-minute group,180-minute group,and 270-minute group(P<0.01),but not in the 45-minute group (P>0.05). As shown by double fluorescent labeling,the distance was sorted in an order of 90-minute group>180-minutes group>270-minute group>45-minutes group>control group.</p><p><b>CONCLUSION</b>The 50-Hz 0.1-mT sinusoidal electromagnetic field can effectively increase bone mineral density and improve bone morphology;however,the intervention effectiveness differs at different time points,with the best effectiveness seen at 90 minutes.</p>