【作者】 沈晶；

【导师】 卜淑敏；

【作者基本信息】 首都体育学院 ， 运动人体科学， 2011， 硕士

【摘要】 实验目的:绝经后骨质疏松症是女性绝经后常见的一种疾病。本研究采用去卵巢大鼠模型模拟女性绝经后骨质疏松状况,探讨中等强度跑台运动减缓去卵巢大鼠骨量丢失的作用机制。实验方法:将60只3月龄雌性SD大鼠按体重随机分为假手术(Sham)、去卵巢静止(OVX)和去卵巢运动(EX)三个组。手术后第2周,去卵巢运动组大鼠先在小动物跑台上开始适应训练1周,然后每周进行4次/45min、速度18m/min、坡度5°的跑台训练。所有运动训练均在上午进行,各组大鼠同等条件饲养。期间每周称量各组大鼠的体重及进食量。正式运动训练15周后,将每组大鼠按体重又随机分为两个亚组,分别在去卵巢16和32周,称量各组大鼠体重,检测大鼠活体全身及主要部位骨密度及体成分后,腹主动脉取血后处死,收集腹腔内脂肪、子宫、股骨下脂肪、骨骼肌以及骨组织并称重。用双能X射线骨密度仪检测离体股骨、胫骨、第5腰椎骨密度和骨矿物含量后用股骨三点弯曲方法检测股骨生物力学性能指标的变化。实验结果:去卵巢16周后:(1)OVX-16组大鼠的体重、体重指数、进食量、脂肪重量、体脂含量、腹腔脂肪和股骨下脂肪显著高于Sham-16组;子宫重量、瘦体含量、左右股骨湿重灰重及去脂肪干重的相对重量和血清钙的含量均显著低于Sham-16组;与OVX-16组比较,EX组大鼠的体脂重量、体脂含量、瘦体重含量、腹腔脂肪、股骨下脂肪、趾长伸肌重量、股骨湿重和去脂肪干重的相对重量有显著性差异,但体重、体重指数、子宫重量、血清钙和磷含量差异无显著性。(2)与Sham-16组比较,OVX-16组大鼠在体全身、腰椎、股骨骨密度显著降低,离体的股骨远端BMD和BMC,胫骨的近端和远端的BMD和BMC显著降低,经过跑台运动训练后,EX组大鼠的在体全身、腰椎BMD均显著升高,离体股骨远端BMD和BMC,胫骨的近端BMD和远端BMC显著升高;(3)相关性分析表明,Sham-16组大鼠的瘦体重与全身骨密度呈显著性正相关,OVX-16组大鼠的体重、瘦体重与全身骨密度均显著正相关,腹腔脂肪与腰椎BMD显著正相关;EX组大鼠的体重、瘦体重与全身BMD显著正相关,左股骨下脂肪与股骨中段BMD显著正相关,右股骨下脂肪与股骨近端和中段BMD显著正相关,腹腔脂肪与股骨近端和远端BMD显著性正相关。(4)OVX-16组大鼠最大载荷、弹性载荷、破坏载荷、最大应力、弹性应力、最大应变、弹性应变均显著小于Sham-16组,经过跑台运动处理后,EX组大鼠的最大载荷、弹性载荷、破坏载荷、最大挠度、最大应力、弹性应力、最大应变、弹性应变均显著大于OVX-16组。去卵巢32周,经过停训处理后,与OVX-32组相比:(1)D-EX组大鼠的进食量显著升高;体重、体重指数、腹腔脂肪升高,但差异无显著性。(2)D-EX组大鼠的全身、腰椎、股骨BMD虽然高于OVX-32组,但差异无显著性;(3)相关性分析表明,Sham-32组大鼠体重与骨密度无显著性相关;瘦体重与全身骨密度、股骨骨密度呈显著正相关关系;OVX-32组大鼠的体重、体脂重量与全身骨密度和股骨骨密度极显著正相关;D-EX组大鼠的体重与骨密度呈正相关关系,体脂重量与全身骨密度、腰椎骨密度和股骨骨密度显著正相关,离体腹腔脂肪重量与腰椎BMD显著正相关。(4)OVX-32组大鼠最大载荷、破坏载荷、最大应力、弹性应力均显著低于Sham-32组,停训后,D-EX组大鼠的弹性载荷、破坏载荷、弹性应力显著高于OVX-32组。实验结论:中等强度跑台运动能:(1)使去卵巢大鼠的体脂重量降低,体脂含量降低,瘦体重含量增加,优化体成分;(2)减缓去卵巢大鼠骨量的丢失;(3)减少去卵巢大鼠股骨胫骨无机矿物质含量的丢失;(4)改善和提高去卵巢大鼠的股骨生物力学性能。但除了骨生物力学性能外,以上效应会由于停训而减弱或消失。(5)大鼠去卵巢后血钙浓度明显降低,血磷降低无显著性意义。运动对血清的钙磷影响无显著性意义。骨密度和体成分的相关性:(1)去卵巢16周后,体重是影响去卵巢大鼠骨密度的重要因素,各组大鼠骨密度与瘦体重密切相关,与脂肪重量无关;(2)去卵巢32周后,去卵巢大鼠骨密度与体重、体脂重量均密切正相关。(3)离体去卵巢大鼠的腹腔脂肪与腰椎骨密度密切相关,股骨下脂肪与股骨近端和中段骨密度密切相关。更多还原

【Abstract】 Objective: Postmenopausal osteoporosis is a common disease in postmenopausal women. In this study, we take ovariectomized female rats as the model of postmenopausal osteoporosis. To explore the mechanism of moderate-intensity treadmill exercise on the loss of bone mass in ovariectomized rats.Methods: Sixty female SD rats were randomly divided into following three groups: sham-operation (Sham), ovariectomized (OVX) and ovariectomized exercised (EX, 18 m/minute, 45 min/day, 5 uphill, 4 times/week). All exercise training was conducted in the morning, feeding the rats in the same conditions. Weigh the body weight of rats and food intake every week. After formal training for 15 weeks, the rats in each group were randomly divided into subgroups, weighing the weight of rats in each group after ovariectomized for 16 and 32 weeks respectively; detected the the bone mineral density (BMD) and body composition in whole body and major parts of body, collected and weighed abdominal fat, uterus, the fat under femur, muscle and bone tissue. Bone mineral density (BMD) and bone mineral content (BMC) of isolated femur, tibia and L5 lumbar were detected by dual energy X-ray, and detect the femur bone biomechanics by the three-point bending method.Result: After ovariectomized for 16 weeks: (1) The body weight, Lee’s, food intake, fat mass, fat content, abdominal fat and hip fat in OVX-16 group were significantly higher than Sham-16 group; the uterine weight, lean mass content, the relative weight of wet、ash and dry femur in both left and right and the levels of Ca、P in serum were significantly lower than Sham-16 group; Compared with OVX-16, fat mass, fat mass content, lean mass content, abdominal fat, fat under the femur, extensor digitorum longus weight, the relative weight of wet and dry femur in EX group were significantly different, but body weight, Lee’s, uterine weight, the calcium and phosphorus content in serum have no significant difference. (2) Compared with Sham-16 group, BMD of the whole body、lumbar spine and femur,BMD and BMC of distal femur,BMD and BMC of the proximal and distal tibia in OVX-16 decreased significantly;After treadmill exercise training, BMD of the whole body、lumbar spine,BMD and BMC of the distal femur,BMD of proximal tibia,BMC of distal tibia in EX increased significantly; (3) Correlation analysis showed that, lean mass was significantly positively correlated with BMD of the whole body in Sham-16 group; Body weight, lean mass were significantly positively related to BMD of the whole body in OVX-16; abdominal fat was positively related to lumbar spine BMD in OVX-16; Body weight and lean mass were significantly positively related to BMD of the whole body in EX; Fat under left femur was significantly positively related to middle femur BMD in EX; Fat under right femur was significantly positively related to proximal and mid-BMD, abdominal fat and the proximal and distal femoral BMD has a significant positive correlation in EX. (4) Maximum load, elastic load, failure load, maximum stress, elastic stress, maximum strain, elastic strain in OVX-16 group was significantly lower than that of Sham-16 group; After treadmill exercise treatment, maximum load, elastic load, failure load, maximum deflection, maximum stress, elastic stress, maximum strain, elastic strain in EX were significantly higher than that of OVX-16 group.After ovariectomized for 32 weeks, compared with OVX-32 group: (1) Food intake was significantly increased; Body weight, Lee’s, abdominal fat increased, but no significant difference in D-EX. (2) Although BMD of the whole body, lumbar spine and femur in D-EX is higher than OVX-32 group, but no significant difference; (3) Correlation analysis showed that, body weight had no significant related with BMD, lean mass was significantly positively correlated with BMD and femur BMD in Sham-32 group; Body weight and fat mass was significantly positively correlated with BMD and femoral BMD in OVX-32; body weight and BMD have a positive correlation with each other, fat mass was significantly positively related to the whole body, lumbar spine and femoral BMD, abdominal fat was positively correlated with lumbar spine BMD in D-EX group; (4) Maximum load, failure load, maximum stress, elastic stress in OVX-32 group were significantly lower than Sham-32 group, after detraining, elastic load, failure load, elastic stress in D-EX were significantly higher in OVX-32 group.Conclusion: Moderate-intensity treadmill exercise can: (1) reduce the fat mass, fat mass content in ovariectomized rats, increased lean mass content, optimize body composition; (2) slow the loss of bone mass in ovariectomized rats; (3 ) decrease the loss of both femur and tibial’s inorganic mineral content in ovariectomized rats; (4) improve bone biomechanical properties of the femur in ovariectomized rats. But except bone biomechanical properties, the above effects are becoming weakened or disappeared due to detraining. (5) The level of calcium, phosphorus in serum in ovariectomized rats was significantly lower; the level of phosphorus in serum has no significant decrease. Effects of exercise on calcium and phosphorus in serum had no significant meaning.Correlation between BMD and body composition: (1) 16 weeks after ovariectomy, body weight is an important factor to bone mineral density in ovariectomized rats and lean body mass and bone mineral density is closely related to each other; (2) 32 weeks after ovariectomized, body weight, fat mass in ovariectomized rats are closely correlated with BMD. (3) Abdominal fat in ovariectomized rats is closely related with the lumbar spine bone mineral density, fat under femur is closely related to the proximal and middle femur BMD.更多还原