中等强度跑台运动对去卵巢大鼠后肢骨骨矿物含量和骨密度的双重调节作用

Dual effects of moderate treadmill exercise on bone mineral content and bone mineral density of hind limb in ovariectomized rats

目的观察中等强度跑台运动对去卵巢大鼠后肢骨骨矿物含量(BMC)和骨密度(BMD)的影响。方法将60只3月龄未经产雌性SD大鼠按体重随机分为假手术、去卵巢静止、去卵巢运动Ⅰ、去卵巢运动Ⅱ、去卵巢运动Ⅲ和去卵巢运动Ⅳ6个组。各运动组经1周的跑台适应训练后,按实验设计分别进行为期14周的正式跑台训练。实验结束时,腹主动脉取血处死大鼠,双能χ-射线骨密度仪检测右侧游离股骨和胫骨的BMC和BMD。结果①与假手术组相比,去卵巢静止组股骨近端和远端以及胫骨近端BMC和BMD显著下降,但股骨中段以及胫骨中段和远端BMC和BMD无显著变化。②与去卵巢静止组相比,去卵巢运动Ⅰ组股骨近端和远端BMC显著增加,股骨中段以及胫骨3个部位BMC均无显著变化;去卵巢运动Ⅱ组和Ⅲ组股骨和胫骨3个部位BMC均无显著变化;去卵巢运动Ⅳ组股骨3个部位BMC均无显著变化,而胫骨3个部位BMC均显著下降。③与去卵巢静止组相比,去卵巢运动Ⅰ组股骨近端和远端以及胫骨近端BMD显著增加,而股骨中段和胫骨中段和远端BMD无显著变化;去卵巢运动Ⅱ组和Ⅲ组股骨和胫骨任何部位BMD均没有显著变化;去卵巢运动Ⅳ组股骨3个部位BMD无显著变化,而胫骨3个部位BMD却显著下降。结论较低中等强度跑台运动能减缓去卵巢大鼠股骨近端和远端骨矿物含量和骨密度的下降;而较高中等强度跑台运动却能加速去卵巢大鼠胫骨近端骨矿物含量和骨密度的下降。

Objective To observe the effects of moderate intensity exercise on bone mineral content （BMC） and bone mineral density （BMD） in ovariectomized rats. Methods Sixty 3-month-old female SD rats were either sham-operated （SHAM） or ovariectomized （OVX） and randomly divided into six groups by body weight： SHAM group, OVX group, exercised OVX group Ⅰ , exercised OVX group Ⅱ , exercised OVX group Ⅲ, exercised OVX grouplV. After one week of adaptation training, exercise groups began official training for 14 weeks according to experimental design. At the end of the experiment, blood was collected from abdominal vein with general anesthesia. BMC and BMD of right femur and tibia were measured by dual-energy X-ray absiorptiometry. Results （1） As expected, OVX resulted in loss of the proximal and distal femur as well as the proximal tibia BMC compared with the SHAM group, as well as the BMD. However, the middle femur BMC and BMD and the middle and distal tibia BMD had no significantly change. （2） The proximal and distal femur BMC increased remarkably in groupⅠ as compared to OVX group, but no difference was observed in middle femur and the three-site tibia. Compared with the OVX group, any sites of the femur and tibia BMC had no significantly change in group Ⅱ and Ⅲ. Any sites of the femur BMC had significant difference in group Ⅳ as compared to OVX group, while significantly decreased in tibia. （3） BMD in the proximal and distal femur and the proximal tibia were significantly increased in exercise group Ⅰ as compared to OVX group, but the middle femur BMD and the middle and distal tibia BMD had no significant difference. Any sites of the femur and tibia BMD had no significantly change in exercise group H and m ~ The exercise group IV had significantly lower tibia BMD than those of the OVX group, but no significant change was observed in the thrce-site femur BMD. Conclusion The lower moderate-treadmill exercise could mitigate femoral bone loss in ovariectomized rats, however, the higher moderate-treadmill exercise could fasten tibia bone loss.