Hughes William E, Ueda Kenichi, Casey Darren P
Department of Physical Therapy and Rehabilitation Science;
Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, Iowa.
J Appl Physiol (1985). 2016 Jun 1;120(11):1335-42. doi: 10.1152/japplphysiol.00057.2016. Epub 2016 Mar 31.
Aging is associated with attenuated contraction-induced rapid onset vasodilation (ROV). We sought to examine whether chronic exercise training would improve ROV in older adults. Additionally, we examined whether a relationship between cardiorespiratory fitness and ROV exists in young and older adults. Chronically exercise-trained older adults (n = 16; 66 ± 2 yr, mean ± SE) performed single muscle contractions in the forearm and leg at various intensities. Brachial and femoral artery diameter and blood velocity were measured using Doppler ultrasound. Vascular conductance (VC) was calculated as the quotient of blood flow (ml/min) and mean arterial pressure (mmHg). These data were compared with our previously published work from an identical protocol in 16 older untrained (66 ± 1 yr, mean ± SE) and 14 young (23 ± 1 yr) adults. Peak (ΔVCpeak) and total vasodilator (VCtotal) responses were greater in trained compared with untrained older adults across leg exercise intensities (P < 0.05). There were no differences in responses between trained older and young adults in the arm or leg at any exercise intensity (P > 0.05). Comparison of ΔVCpeak in a subset of subjects at an absolute workload in the leg revealed that trained older adults exhibited augmented responses relative to untrained older adults. Exercise capacity (V̇o2 peak) was associated with ΔVCpeak and VCtotal across arm (r = 0.59-0.64) and leg exercise intensities (r = 0.55-0.68, P < 0.05) in older adults. Our data demonstrate that 1) chronic exercise training improves ROV in the arm and leg of trained older adults, such that age-related differences in ROV are abolished, and 2) VO2peak is associated with ΔVCpeak responses in both limbs of older adults.
衰老与收缩诱导的快速血管舒张（ROV）减弱有关。我们试图研究长期运动训练是否能改善老年人的ROV。此外，我们还研究了年轻和老年成年人的心肺适能与ROV之间是否存在关联。长期接受运动训练的老年人（n = 16；66±2岁，均值±标准误）在前臂和腿部进行了不同强度的单肌肉收缩。使用多普勒超声测量肱动脉和股动脉直径及血流速度。血管传导率（VC）计算为血流量（毫升/分钟）与平均动脉压（毫米汞柱）的商。这些数据与我们之前发表的、采用相同方案对16名未受过训练的老年人（66±1岁，均值±标准误）和14名年轻人（23±1岁）进行研究所得的数据进行了比较。在腿部不同运动强度下，与未受过训练的老年人相比，受过训练的老年人的峰值（ΔVCpeak）和总血管舒张反应（VCtotal）更大（P < 0.05）。在任何运动强度下，受过训练的老年人与年轻人在手臂或腿部的反应均无差异（P > 0.05）。对一部分受试者在腿部绝对工作量下的ΔVCpeak进行比较发现，与未受过训练的老年人相比，受过训练的老年人表现出增强的反应。在老年人中，运动能力（峰值摄氧量）与手臂（r = 0.59 - 0.64）和腿部不同运动强度下的ΔVCpeak及VCtotal相关（r = 0.55 - 0.68，P < 0.05）。我们的数据表明：1）长期运动训练可改善受过训练的老年人手臂和腿部的ROV，从而消除ROV中与年龄相关的差异；2）峰值摄氧量与老年人双下肢的ΔVCpeak反应相关。
