正弦交变电磁场提高大鼠峰值骨量存在时间效应  

A time effect in sinusoidal alternating electromagnetic field to improve peak bone mass in rats

作　　者：高玉海[1] 李唯[1] 陈克明[2] 周建[2] 成魁[2] 马小妮[2] 石文贵[2] 李少锋[1] 

机构地区：[1]甘肃农业大学生命科学技术学院,兰州730070 [2]兰州军区兰州总医院骨科研究所,兰州730050

出　　处：《第三军医大学学报》2014年第15期1557-1561,共5页Journal of Third Military Medical University

基　　金：国家自然科学基金(81270963);甘肃省科技重大专项计划(092NKDA025)~~

摘　　要：目的探讨50 Hz 0.1 mT正弦交变电磁场(sinusoidal electromagnetic fields,SEMFs)不同时长暴露干预对SD大鼠峰值骨量(peak bone mass,PBM)的影响。方法 6周龄雌性SD大鼠50只,按随机数字表法分为正常对照组、45 min组、90 min组、180 min组和270 min组。除正常对照组外,各实验组每天给予相应时长50 Hz 0.1 mT磁场强度的SEMFs干预。8周后采用双能X射线骨密度仪检测骨密度,AG-X系列台式电子万能试验机检测椎体生物力学性能,ELISA法测定血清骨钙素(osteocalcin,OC)和抗酒石酸酸性磷酸酶5b(tartrate-resistant acid phosphatase 5b,TRACP 5b)浓度,品红-苦味酸染色(Van Gieson,VG)进行骨形态分析。结果与正常对照组相比:90 min组大鼠全身骨密度、股骨骨密度、椎体骨密度、椎体生物力学参数和血清中OC的含量均增加,差异均有统计学意义(P<0.01);180 min组股骨、椎体骨密度和血清中OC、全身骨密度及生物力学均增加,差异有统计学意义(P<0.05);270 min组股骨骨密度和椎体骨密度增加,差异有统计学意义(P<0.01),其余指标差异均无统计学意义(P>0.05);45 min组各指标差异均无统计学意义(P>0.05);各组血清TRACP 5b的含量无明显变化。90、180、270 min组骨小梁数目、厚度和面积均增加,而骨小梁间隙均减小,差异具有统计学意义(P<0.01),45 min组无明显差异(P>0.05)。结论 50 Hz 0.1 mT磁场强度提高了SD大鼠峰值骨量,但是存在时间"窗口效应",90 min效果最好,不同时长对峰值骨量的提高有明显的差异。Objective To determine the effect of different durations of 50 Hz 0. 1 mT sinusoidal electromagnetic fields （SEMFs） on the peak bone mass （PBM） of rats. Methods Fifty female SD rats were randomly and equally divided into 5 groups, that is, control group, 45 min group, 90 min group, 180 min group and 270 min group. In addition to control group, the other experimental groups were exposed to 50 Hz O. 1 mT magnetic field every day for corresponding time periods. After 8 weeks, their bone mineral densities （BMD） of whole body were examined by DEXA. The effects were evaluated by measurements of bone biomechanical properties of femurs and vertebrae, serum levels of osteocalcin （OC） and tartaric acid phosphatase 5b （TRACP 5b）, and histomorphometry. Results Compared with the control group, the body BMD, femoral, vertebral bone mineral density, vertebral biomechanieal parameters and serum OC level of 90 min group were increased, the differences were statistically significant （P 〈0.01 ）. Femur, vertebral body bone mineral density and serum OC of 180 min group were increased, with significant differences （P 〈 0.05 ）. Femur bone density and vertebral bone mineral density of 270 min group were increased with statistical differences （P 〈 0.01 ）, but no significant difference was seen in the rest of the indicators （ P 〉 0.05 ）. There was no significant difference in each index between the 45 min group and the control （P 〉 0.05 ）. Serum TRACP 5b in each group showed no significant change （P 〉 0.05 ）. The trabecular number, thickness and area were all increased, and the trabecular space were narrowed, with statistically differences compared with 90 min group, 180 min group, and 270 min group （P 〈 0.01 ）, but not with 45 min group （P 〉 0.05 ）. Conclusion Magnetic field of 50 Hz 0.1 mT strengthes the peak bone mass in rats. But there is a time ＂window＂ effect, and 90 min is best. Different times show different significances in increasing peak bone mass.

关 键 词：正弦交变电磁场 骨密度 峰值骨量 骨质疏松症 大鼠 

分 类 号：R122.4[医药卫生—环境卫生学] R336[医药卫生—公共卫生与预防医学]