极低频脉冲电磁场结合全身振动对大鼠用性骨质疏松影响的实验研究

摘要

目的 探讨脉冲电磁场结合全身振动对悬吊诱导的废用性骨质疏松大鼠骨密度、骨微结构和骨生物力学性能的影响.方法 选取4月龄雌性SD大鼠40只,随机分为5组:空白组为健康大鼠作为正常对照;对照组为废用性骨质疏松大鼠模型;极低频脉冲电磁场电组(extremely low-frequency pulsed electromagnetic field,ELF-PEMFs),给予极低频脉冲电磁场干预;全身振动组(whole-body vibration,WBV),给予全身振动干预;极低频脉冲电磁场联合全身振动组(extremely low-frequency pulsed electromagnetic field +whole-body vibration,ELF-PEMFs+WBV),给予极低频脉冲电场磁联合全身振动干预.除空白组外同时对其它4组后肢悬吊6周行废用性骨质疏松造模.造模成功后,空白组和对照组不给予任何治疗,其他3组连续物理治疗8周后,记录各组大鼠的体重,使用双能X线测量治疗前后骨密度,处死大鼠后取右股骨标本行Mi-cro-CT分析骨微结构、取左侧股骨进行生物力学性能检测.结果 连续治疗8周后,与对照组比较,ELF-PEMFs组、WBV组、ELF-PEMFs+WBV组大鼠体重、骨密度值均显著增加,差异有统计学意义[(PELF-PEMFa=0.015,PWBV组=0.016,PELF-PEMFa+WBV组=0.007),(tELF-PEMFa组=5.956,PELF-PEMFa组=0.000;tWBV 组=6.127,PBv组=0.000;tELF-PEMFa+WBV组=4.639,PELF-PEMFa+WBV组=0.000)];组间比较ELF-PEMFs+WBV组较ELF-PEMFs组和WBV组增加更明显,差异有统计学意义(F=0.091,P=0.018).Micro-CT分析:ELF-PEMFs组、WBV组、ELF-PEMFs+WBV组骨矿化体积分数(bone volume per tissue volume,BV/TV)、骨小梁的数量(trabecular number,Tb.N)、骨小梁厚度(trabecular thickness,Tb.Th)、结构模型指数(structure model index,SMI)升高,而骨小梁分离度(trabecular separation,Tb.Sp)、骨小梁连接密度(connectivity density,Conn.D)降低,骨小梁结构都有改善,而ELF-PEMFs+WBV组较其他两组更明显,差异有统计学意义[与ELF-PEMFs组对比,PBWV=0.041,PTbN=0.026,PTb、Th=0.009,PConn.D=0.030,PTb.Sp=0.045,PSWI=0.032);与WBV组对比,PBV/TV=0.018,PTb.N=0.004,PTb.Th=0.022,PConn.DD=0.042,PTb.Sp=0.039,PSMI=0.049)];生物力学性能测试:ELF-PEMFs组、WBV组、ELF-PEMFs+WBV组最大载荷、能量吸收、骨骼刚度指标都与对照组有差异,ELF-PEMFs+WBV组较其他两组治疗结合组有显著提高(F=0.167,P=0.038).结论 极低频脉冲电磁场结合全身振动治疗可提高废用性骨质疏松大鼠骨密度,改善骨小梁微结构,提高骨生物力学性能,而两者有协同作用,治疗效果优于单一治疗.%Objective To discuss the effect of low-frequency pulsed electromagnetic field (ELF-PEMFs) combined with-whole-body vibration(WBV) on the bone mineral density,bone microstructure and the biological mechanics performance inhindlimb unloading osteoporosis rats.Methods Forty female 4 months aged SD rats were randomly divided into five groups:blank group,control group,ELF-PEMFs group,WBV group,low-frequency pulsed electromagnetic field combined with wholebody-vibration(ELF-PEMFs + WBV) group.The blank group was the normal control which comprise the healthy rats.The controlgroup was the disused osteoporosis model.Except for the blank group,thehind limb unloading rats were kept for six weeks.No intervention were provided to the blank group and the control group,other three groups were treated with physical therapy.The bodyweight of rats in each group was record.Bone mineral density was measured by Dual energy X-ray absorptiometry.The right femurs was analyzed by Micro-CT and the left femur was tested through a biomechanical machine.Results After 8 weeks of continuous treatment,the ELF-PEMFs group,WBV group,ELF-PEMFs+WBV group were significantly increased in weight and bonedensity (PELF-PEMFs=0.015,PWBV=0.016,PELF-PEMFs+WBV=0.007),(tELF-PEMFs=5.956,PELF-PEMFs=0.000;tWBV=6.127,PWBV=0.000;tELF-PEMFs+WBV=4.639,PELF-PVMFs+WBV=0.000).The difference was statistically significant (F=0.091,P=0.018).The ELF-PEMFs +WBV group was significantly higher in bone formation index.The items of BV/TV,Tb.N,Tb.Th and SMI in Micro-CT analysis increased,while Tb.Sp and Conn.D index decreased significantly.Trabecular bone structure of all the three groups was improved,however the ELF PEMFs +WBV group was better than the other two groups (vs.ELF-PEMF group,PBV/TV=0.041,PTb.N=0.026,PTb.Th=0.009,PConn.D=0.030,PTb.Sp=0.045,PSMI=0.032;VS.WBV group,PBv/Tv=0.018,PTb.N=0.004,PTb.Th=0.022,PConn.D=0.042,PTb.Sp=0.039,PSMI=0.049).The maximum load,energy absorption and bone stiffness index in biomechanicalperformance test were improved.The combination treatment group were significantly improved (F=0.167,P=0.038).Conclusion Low-frequencypulsed electromagnetic field combined with whole body vibration therapy can improve bone mineral density,bone microstructureand the biological mechanics performance.They have synergistic effect and the combination therapy is better than single treatment.