Effect of low intensify pulsed electromagnetic fields on bone mineral density of different anatomic region in ovariectomized rats

Objective To explore the effect of low intensify pulsed electromagnetic fields on bone mineral density of different anatomic region in ovariectomized rats.Methods Thirty 10-month-old female Sprague-Dawley rats were randomly divided into three different groups:ovariectomized control group(OVX group),normal control group(SHAM group) and pulsed electromagnetic fields exposing group(PEMFs group).All rats were subjected to bilateral ovariectomy except those in SHAM group,and the PEMFs group were exposed to pulsed electromagenetic fields with frequency 50 Hz,peak magnetic induction density 0.16 mT and exposure time 60 minute per day.In the experimental period,bone mineral density(BMD) of general and cranioaural BMD were observed dynamically,eventually,the level of estradiol and the BMD were measured.Results ①In the SHAM group,the level of estradiol and the coefficient of uterus were significantly higher than other two groups(P0.01);②Compared with SHAM group and PEMFs group,the cranioaural BMD of OVX group were decreased significantly on the 60th day(P0.05),while the significantly difference of general BMD was detected until the 90th day(P0.05);③The difference in centrum vertebrae BMD of OVX group were more markedly than in lumbar vertebrae of BMD compared with SHAM group and PEMFs group,the femoral BMD of PEMFs group rose compared with OVX group,but the distinction did not reach the statistical significance.Conclusion Combining general BMD with cranioaural BMD can accurately assess dynamic variation on the BMD of alive rats;This pulsed electromagnetic fields could suppress the reduction of BMD conspicuously in bilateral ovariectomized rats,at the same time,they have different effect on BMD of different anatomic region;It will reflect the changes in bone masses with good precision by measuring the pyramidal BMD.