Caulkins Carrie, Ebramzadeh Edward, Winet Howard
Department of Biomedical Engineering, University of California, Los Angeles, California 90095, USA.
J Orthop Res. 2009 May;27(5):651-6. doi: 10.1002/jor.20780.
The direct and indirect effects of muscle contraction on bone microcirculation and fluid flow are neither well documented nor explained. However, skeletal muscle contractions may affect the acquisition and maintenance of bone via stimulation of bone circulatory and interstitial fluid flow parameters. The purposes of this study were to assess the effects of transcutaneous electrical neuromuscular stimulation (TENS)-induced muscle contractions on cortical bone blood flow and bone mineral content, and to demonstrate that alterations in blood flow could occur independently of mechanical loading and systemic circulatory mechanisms. Bone chamber implants were used in a rabbit model to observe real-time blood flow rates and TENS-induced muscle contractions. Video recording of fluorescent microspheres injected into the blood circulation was used to calculate changes in cortical blood flow rates. TENS-induced repetitive muscle contractions uncoupled from mechanical loading instantaneously increased cortical microcirculatory flow, directly increased bone blood flow rates by 130%, and significantly increased bone mineral content over 7 weeks. Heart rates and blood pressure did not significantly increase due to TENS treatment. Our findings suggest that muscle contraction therapies have potential clinical applications for improving blood flow to cortical bone in the appendicular skeleton.
肌肉收缩对骨微循环和流体流动的直接和间接影响既没有得到充分的记录，也没有得到很好的解释。然而，骨骼肌收缩可能通过刺激骨循环和组织液流动参数来影响骨的获取和维持。本研究的目的是评估经皮电神经肌肉刺激（TENS）诱导的肌肉收缩对皮质骨血流量和骨矿物质含量的影响，并证明血流量的改变可以独立于机械负荷和全身循环机制而发生。在兔模型中使用骨腔植入物来观察实时血流速率和TENS诱导的肌肉收缩。通过对注入血液循环的荧光微球进行视频记录来计算皮质血流速率的变化。与机械负荷无关的TENS诱导的重复性肌肉收缩瞬间增加了皮质微循环流量，使骨血流量直接增加了130%，并在7周内显著增加了骨矿物质含量。TENS治疗后心率和血压没有显著升高。我们的研究结果表明，肌肉收缩疗法在改善四肢骨骼皮质骨血流方面具有潜在的临床应用价值。
