不同治疗时间脉冲电磁场对去势大鼠血清雌二醇及股骨骨钙含量的影响

Effect of pulsed electromagnetic fields of different treatment time on serum estradiol and bone calcium content of femur in ovariectomized rats

目的:研究不同治疗时间PEMFs干预去势大鼠骨质疏松模型各组大鼠的血清雌二醇及股骨骨钙含量的变化,探求PEMFs治疗骨质疏松的最适治疗时间。方法:按随机分组原则用密闭信封法将雌性3月龄SD大鼠50只分为5组:SHAM对照组、OVX对照组、OVXⅠ组、OVXⅡ组、OVXⅢ组每组10只。除SHAM对照组以外,对所有动物按文献方法切除双侧卵巢去势造模。OVXⅠ组、OVXⅡ组和OVXⅢ组三组大鼠每天在强度为3.8mT,频率为8Hz的磁场环境中分别接受治疗,20、40、60min/d,共30d。SHAM对照组和OVX对照组不干预。各组动物均在满30d后股动脉放血处死,取血清标本做血清雌二醇测定,并取左侧股骨作骨钙含量测定。结果:SHAM对照组大鼠的血清雌二醇水平均显著高于其他四组大鼠的血清雌二醇水平(P<0.05或P<0.01),但其他4组大鼠的血清雌二醇水平之间的差异无显著性(P>0.05)。OVX对照组大鼠股骨骨钙含量显著低于其他四组大鼠(P<0.01),但其他四组大鼠的股骨骨钙含量之间的差异无显著性(P>0.05)。结论:在磁场强度(3.8mT)和脉冲频率(8Hz)相同的前提下,三种治疗时间的PEMFs并不能提高去势大鼠血清雌二醇的水平,但均能阻止大鼠在卵巢切除后的骨钙含量下降。三种治疗时间的PEMFs均能使OVX大鼠股骨骨钙含量维持在接近正常的水平,但差异无显著性,说明每日用PEMFs对去势大鼠治疗20—60min,对其骨钙含量的维持效果相同。

Objective：To observe the effect of pulsed electromagnetic fields（PEMFs） of different treatment time on serum estradiol and bone calcium content of femur in ovariectomized rats,so as to find out the best effective treatment time. Method：Fifty female SD rats were randomly divided into five groups： ①SHAM control （no PEMFs treatment）,②OVX control（no PEMFs treatment）,③OVX Ⅰ （PEMFs treatment at 8Hz frequency with 3.8roT intensity, 20rain daily for 30 days）, ④OVX Ⅱ（PEMFs treatment at 8Hz frequency with 3.8mT intensity,40min daily for 30 days）,and ⑤OVXⅢ （PEMFs treatment at 8Hz frequency with 3.8mT intensity,60min daily for 30 days）. All rats were subjected to bilateral ovariectomy except those in the SHAM control group. Serum estradiol （E2） and bone calcium content of femur were assessed on the 30th days after PEMFs treatment. Result：The E2 values of the SHAM control group were significantly higher than that of the other 4 groups （P〈0.05 or P〈0.01）,but the difference in E2 values was not significant among the other 4 groups（P〉0.05）. The bone calcium contents of the OVX control group were significantly lower than that of the other 4 groups （P〈0.01）,but the difference of calcium contents was not significant among the other 4 groups （P〉0.05）.Coneluslon：Under certain intensity（3.8mT） and frequency （8Hz）, PEMFs of the three different treatment time can＇t significantly improve serum estradiol level in ovariectomized rats. PEMFs of the three different treatment time can significantly maintain bone calcium content of femur approximately to the normal level in ovariectomized rats,but among the three groups,the difference is not significant. It shows that PEMFs have the same effect of maintaining bone calcium content with no correlation of increasing the treatment time within the range of 20-60min in ovariectomized rats.