复合振动对卵巢切除大鼠骨质量的作用

Effect of compound vibration on bone quality of ovariectomized rats

背景:目前所使用的全身振动防治骨质疏松所需振动强度较大,人体不适感较强。作者设计了复合振动,前期实验发现复合振动可在更低强度下有效预防卵巢切除大鼠的骨密度下降。目的:课题创新性提出低强度复合振动可维持生长期卵巢切除SD大鼠骨质量的理论假设,并期望实验结果加以验证。方法:SPF级4月龄雌性未育SD大鼠32只,随机分为正常对照组、卵巢切除组以及振动1、振动2组,每组大鼠均为8只。振动1组接振45～55Hz,0.05～0.1g;振动2组接振45～55Hz,0.12～0.21g。振动20min/次,1次/d,5次/周,休息间隔不大于2d。实验时间13周。观察振动干预前后大鼠活体骨密度,体外标本骨微结构以及生物力学性能。结果与结论:卵巢切除组腰椎骨密度下降(P<0.05),而正常对照组与两振动组有显著性增加,股骨骨密度均增加,组间差异无显著性意义;卵巢切除各组骨微结构参数均明显下降,但振动2组骨小梁数量、骨小梁厚度、骨小梁间距、骨体积分数相对于卵巢切除组有显著改善;腰椎骨强度值两振动组较卵巢切除组显著增加(P=0.025、0.006),与正常对照组比较差异无显著性意义。实验结果证明,特定的复合振动舒适感较好的低强度下可以有效预防卵巢切除SD大鼠骨密度下降,减轻骨微结构破坏程度,维持骨强度,具有改善卵巢切除大鼠骨质量的作用和潜在的预防骨质疏松作用。

BACKGROUND：Whole body vibration which is used to prevent and treat osteoporosis recently is uncomfortable due to its strong vibration strength. The designed compound vibration with low vibration strength could effectively prevent bone quality decrease of ovariectomized rats. OBJECTIVE：To verify the effect of compound vibration with low vibration strength on the bone quality of ovariectomized rats. METHODS：A total of 32 4-month-old female SD rats were used in this study. All SD rats were randomly divided into 4 groups：normal control group,ovariectomized control group,vibration Ⅰ group （45 Hz-55 Hz,0.05 g-0.1 g）,and vibration Ⅱ group （45 Hz-55 Hz,0.12 g-0.21 g）,with 8 rats for each group. The intervention to each vibration group was one a day,20 minutes/times,and 5 days per week. The resting interval was shorted than 2 days,and the whole vibration intervention lasted 13 weeks. Bone mineral density （BMD） before and after vibration,ex vivo bone microstructure parameters and biomechanics parameters were measured in this study. RESULTS AND CONCLUSION：Lumbar BMD of ovariectomized control group was decreased （P 0.05）,but the BMD in the normal control group and the two vibration groups was increased significantly. Femoral BMD of all groups was increased,but there was no significant difference among the four groups. Bone microstructure parameters of the three ovariectomized groups were decreased; however,parameters including number,thickness and distance of bone trabecula and bone volume fraction in the vibration II group were significantly improved compared to ovariectomized control group. Moreover,bone strength of lumbar vertebra in the two vibration groups was significantly increased （P=0.025,0.006）,but there was no significant difference compared to normal control group. Compound vibration with low strength could effectively prevent BMD decrease of ovariectomized rats,lighten the degree of bone microstructure damage,keep bone strength,improve bone quality of ovariectomized rats,and potentially prevent osteoporosis.