运动与17β-雌二醇对去卵巢大鼠血清17β-雌二醇和后肢骨骨密度的影响

目的：观察跑台运动和17β-雌二醇（E2）对去卵巢大鼠血清E2水平和后肢骨骨密度（BMD）的影响。方法：按体重将120只成年雌性SD大鼠随机分为假手术、假手术运动、去卵巢、去卵巢运动、雌激素、雌激素加运动6个组。假手术运动、去卵巢运动和雌激素加运动组每周进行5次60min、18m／min的平坡跑台运动训练，雌激素和雌激素加运动组每周按体重颈部皮下注射3次E2，每次50μg／kg体重。分别在运动和给药正式处理7和14周时，用放射免疫法检测血清E2水平；用双能X线骨密度仪检测右侧胫骨和股骨BMD的变化。结果：运动和给药正式处理7周时，去卵巢组胫骨近端、股骨近端和远端BMD以及血清E2水平均显著低于假手术组；去卵巢运动加E2组股骨近端和远端BMD显著高于去卵巢组，E2组和去卵巢运动加E2组大鼠血清E2水平显著高于去卵巢组。运动和给药正式处理14周时，去卵巢组大鼠胫骨近端、股骨近端和远端BMD以及血清E2水平均显著低于假手术组，假手术运动组股骨近端BMD显著高于假手术组；去卵巢运动组、E2组和去卵巢运动加E2组大鼠血清E2水平显著高于去卵巢组，去卵巢运动组股骨远端BMD显著高于去卵巢组，E2组和去卵巢运动加E2组胫骨近端、股骨近端和远端BMD均显著高于去卵巢组；去卵巢运动组大鼠胫骨近端BMD和血清E2水平显著低于去卵巢运动加E2组，E2组胫骨近端BMD显著高于去卵巢运动加E2组。结论：E2和较高中等强度跑台运动对去卵巢大鼠股骨和胫骨松质骨骨量减缓的效应是独立的。

Effects of Exercise and 17β-Estradiol Replacement on the Serum Level of 17β- Estradiol and the Bone Mineral Density of Hind Limb in Wvariectomized Rats

Objective： To observe the effects of treadmill exercise and 17β- estradiol （E2） replacement treatment on the serum level of E2 and the bone mineral density （BMD） of hind limb in ovariectomized （OVX） rats. Methods： 120 female mature Sprague-Dawley rats were randomly divided into six groups according to their body weight： sham, sham exercise （Sham-EX）, OVX, OVX＋exereise （OVX-E- X）, OVX＋estrodial （E2）, OVX＋exercise＋E2 （OVX-EX-E2）. The exercise rats run 60 min at a speed of 18m/min 5 times per week. E2 was given subcutaneously three times per week at a dose of 50 μg/kg. After sports and drug treatment for 7 weeks or 14 weeks, the serum level of E2 was determined by immunoassay, meanwhile the BMD of right tibia and femur were detected by dual energy X-ray absorptiometry. Results： After sports and drug treatment for 7 weeks, the serum level orE2 and the BMD of proximal tibia, proximal femur and distal femur in OVX rats were significantly lower than those in Sham group. The BMD of proximal femur and distal femur in OVX-EX-E2 group were significantly greater than those in OVX group. The serum level of E2 in E2 group and OVX-EX-E2 group were significantly greater than those in OVX group. After sports and drug treatment for 14 weeks, the serum level of E2 and the BMD of proximal tibia, proximal femur and distal femur in OVX group were significantly lower than those in Sham group. The BMD of proximal femur in Sham-EX group was significantly greater than those in Sham group. The serum level of E2 in OVX-EX group, E2 group, and OVX-EX-F-a group were significantly greater than those in OVX group. The BMD of distal femur in OVX-EX group was significantly greater than those in OVX group. The BMD of proximal femur and distal femur in E2 group and OVX-EX-E2 group were significantly greater than those in OVX group. The serum level of E2 and the BMD of proximal tibia in OVX-EX group were significantly lower than those in OVX-EX-E2 group. The BMD of proximal femur in E2 group was significantly greater than those in OVX-EX-E2 group. Conclusion： E2 and the higher middle-intensity treadmill exercise treatment had independent effect on bone loss of OVX rats.