Age-associated impairments in contraction-induced rapid-onset vasodilatation within the forearm are independent of mechanical factors.
Age-associated impairments in contraction-induced rapid-onset vasodilatation within the forearm are independent of mechanical factors.
复制标题
前臂内收缩引起的快速血管舒张的年龄相关损伤与机械因素无关。
DOI：
10.1113/ep086908
复制
发表时间：
2018
影响因子：
2.7
通讯作者：
Casey,DarrenP
中科院分区：
文献类型：
--
作者：
Hughes,WilliamE;Kruse,NicholasT;Casey,DarrenP
新发现本研究的中心问题是什么？我们研究了收缩诱导的快速发作血管舒张（RADAF）的机械作用是否随年龄而不同，以及RADAF是否与外周动脉僵硬度相关。此外，我们还研究了灌注压的调控是如何调节年轻人和老年人的血压的。主要的发现和重要性是什么？在年轻人和老年人中，机械性因素对癫痫的影响相似。相反，外周动脉僵硬度与动脉粥样硬化无关。在年轻人和老年人中，提高灌注压可使血压增加到相似的程度。这些结果表明，年龄相关的衰减，在血管紧张素转换酶是不属于机械组件和血管紧张素转换酶反应是独立的外周动脉stiffen. AbstractContraction-induced快速起效的血管舒张（血管舒张）调制灌注和跨壁压在年轻人，然而，这种影响仍然是未知的老年人。本研究探讨了机械性因素对老年人动脉硬化的影响，灌注压的影响以及这些反应是否与动脉硬化有关。在12名健康年轻人（24 ± 4岁）和12名老年人（67 ± 3岁）中测量前臂血管传导性（单位：毫升/分钟/100 mmHg）：（i）在最大自主收缩的20%下进行单次动态收缩;和（ii）在心脏水平上方、下方和下方对前臂进行单次外部机械压迫（200 mmHg）。颈动脉-桡动脉脉搏波速度表征上肢动脉僵硬度。在心脏水平，老年人对单次肌肉收缩和单次外部机械按压的总收缩反应减弱（P< 0.05）;然而，年轻人和老年人对收缩诱导峰值的相对机械贡献（46 ± 14 vs 40 ± 18%;P= 0.21）和总反应（37 ± 21 vs 32 ± 18%;P= 0.27）没有差异。降低或提高灌注压改变了年轻人和老年人之间相似程度的电刺激反应（P< 0.05）。在整个组中，上肢动脉僵硬度与峰值（r= 0.02;P= 0.93）或总血管电导（r=-0.01;P= 0.96）无关。我们的数据表明：（i）年龄相关的动脉硬化衰减与机械成分无关;（ii）年轻人和老年人之间灌注压增加动脉硬化的程度相似;（iii）年轻人和老年人单次骨骼肌收缩后，基础上肢动脉僵硬与血管扩张反应无关。
New FindingsWhat is the central question of this study?We examined whether the mechanical contribution to contraction‐induced rapid‐onset vasodilatation (ROV) differed with age and whether ROV is associated with peripheral artery stiffness. Furthermore, we examined how manipulation of perfusion pressure modulates ROV in young and older adults.What is the main finding and its importance?The mechanical contribution to ROV is similar in young and older adults. Conversely, peripheral arterial stiffness is not associated with ROV. Enhancing perfusion pressure augments ROV to a similar extent in young and older adults. These results suggest that age‐related attenuations in ROV are not attributable to a mechanical component and that ROV responses are independent of peripheral artery stiffness.AbstractContraction‐induced rapid‐onset vasodilatation (ROV) is modulated by perfusion and transmural pressure in young adults; however, this effect remains unknown in older adults. The present study examined the mechanical contribution to ROV in youngversusolder adults, the influence of perfusion pressure and whether these responses are associated with arterial stiffness. Forearm vascular conductance (in millilitres per minute per 100 mmHg) was measured in 12 healthy young (24 ± 4 years old) and 12 older (67 ± 3 years old) adults during: (i) single dynamic contractions at 20% of maximal voluntary contraction; and (ii) single external mechanical compression of the forearm (200 mmHg) positioned above, at and below heart level. Carotid–radial pulse‐wave velocity characterized upper limb arterial stiffness. Total ROV responses to single muscle contractions and single external mechanical compressions were attenuated in older adults at heart level (P< 0.05); however, the relative mechanical contribution to contraction‐induced peak (46 ± 14versus40 ± 18%;P= 0.21) and total (37 ± 21versus32 ± 18%;P= 0.27) responses were not different between young and older adults. Reducing or enhancing perfusion pressure altered ROV responses to a similar extent between young and older adults (P< 0.05). Upper limb arterial stiffness was not associated with peak (r= 0.02;P= 0.93) or total vascular conductance (r= −0.01;P= 0.96) in the group as a whole. Our data suggest that: (i) age‐associated attenuations in ROV are not attributable to a mechanical component; (ii) enhancing perfusion pressure augments ROV to a similar extent between young and older adults; and (iii) basal upper limb arterial stiffness is not associated with the vasodilator responses after a single skeletal muscle contraction in young and older adults.