Effects of low intensity PEMFs on bone mineral density and histomorphometry in SD rats

    XU Qiaoª²Ling£¬LU Liª²Hua£¬LUO Erª²Ping, SHEN Guangª²Hao, LIU Dongª²Huan, HUA Qianª²Zhen, WU Xiaoª²Ming, LI Liª²Rong

    1School of Nursing, 2Department of Chemistry, School of Basic Medicine, 3Department of Military Medical Equipment & Metrology, School of Biomedical Engineering, Fourth Military Medical University, Xi¡¯an 710033, China

    ¡¾Abstract¡¿ AIM: To investigate the effects of pulsed electromagnetic fields (PEMFs) on bone mineral density (BMD) and histomorphometry in ovariectomized rats. METHODS: Thirtyª²two female SD rats were divided randomly into 4 groups: ovariectomy, control, magnetic A, magnetic B. All the rats were operated on the abdomen and the rats of ovariectomy group and magnetic groups (A, B) were ovariectomized. The rats of control group only had sham operation and were not ovariectomized. The rats in both magnetic groups were exposed to 15 Hz PEMFs 6 hours per day, with its pulse duration set to 5 ms. Magnetic group A and group B were exposed to PEMFs with different magnetic intensity, 4¡Á10-4 T for group A and 8¡Á10-4 T for group B. All the animals were killed 8 weeks after operation and the changes of BMD and histomorphometric properties were observed. RESULTS: The values of BMD, trabecular area, trabecular thickness and trabecular number in ovariectomized group significantly decreased, compared with those of the other three groups(P<0.05), while the trabecular separation in ovariectomized group increased obviously, compared with magnetic group A and magnetic group B (P<0.05). Compared with those of control group, no significant differences were found in the values of total body BMD, trabecular area and trabecular number in magnetic group B (P>0.05). But, statistically significant differences were observed in the values of total body BMD and trabecular number between the two magnetic groups(P<0.05). CONCLUSION: There are some evident "windowª²effects" during the treatment by PEMFs. PEMFs are effective in improving BMD and histomorphometric values and are favorable to the treatment and prevention of osteoporosis. ......