Gao Yu-Hai, Zhen Ping, Zhou Jian, Ma Xiao-Ni, Yan Juan-Li, Li Shao-Feng, Zhou Yan-Feng, Chen Ke-Ming
Institute of Orthopaedics,Lanzhou General Hospital of Lanzhou Military Area Command of Chinese PLA,Lanzhou 730050,China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2014 Dec;36(6):660-7. doi: 10.3881/j.issn.1000-503X.2014.06.019.
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.
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.
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.
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.
探讨50Hz、0.1mT正弦电磁场在不同时间点对大鼠骨密度（BMD）及骨组织形态计量学的影响。
将50只6周龄雌性SD大鼠随机分为5组：对照组、45分钟组、90分钟组、180分钟组和270分钟组，每组10只。除对照组外，其余4组大鼠每天分别在50Hz、0.1mT正弦电磁场中进行45分钟、90分钟、180分钟或270分钟的磁干预。8周后，采用双能X线吸收法测量大鼠全身BMD、股骨BMD和腰椎BMD。分离左侧胫骨和第五腰椎进行骨组织静态和动态分析。
与对照组相比，90分钟组和180分钟组大鼠全身BMD有显著差异（P<0.01，P<0.05），而45分钟组和270分钟组差异无统计学意义（P>0.05）。90分钟组、180分钟组和270分钟组大鼠股骨、腰椎BMD、血清生化指标及第五腰椎组织静态参数有显著差异（P<0.01），45分钟组差异无统计学意义（P>0.05）。双荧光标记显示，骨小梁间距由大到小依次为90分钟组>180分钟组>270分钟组>45分钟组>对照组。
50Hz、0.1mT正弦电磁场可有效提高大鼠骨密度，改善骨形态；但不同时间点干预效果不同，90分钟时干预效果最佳。
