Endothelial dysfunction following prolonged sitting is mediated by a reduction in shear stress
Endothelial dysfunction following prolonged sitting is mediated by a reduction in shear stress
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DOI：
10.1152/ajpheart.00943.2015
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发表时间：
2016-03-01
影响因子：
4.8
通讯作者：
Padilla, Jaume
中科院分区：
文献类型：
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作者：
Restaino, Robert M.;Walsh, Lauren K.;Padilla, Jaume
我们和其他人最近报道，久坐损害腿部血管内皮功能;然而，其机制仍不清楚。在此，我们测试了一个假设，即持续减少流动引起的剪切应力是潜在的机制，其中坐诱导腿部内皮功能障碍。具体来说，我们研究了是否阻止在坐着时的剪切应力的减少将消除坐着对腘动脉内皮功能的不利影响。在10名年轻健康男性中，在3小时坐姿期之前和之后进行腘动脉血流介导的扩张的双侧测量，在此期间，一只脚浸没在42摄氏度的水中（即，加热）以增加血流并因此增加剪切应力，而对侧腿保持干燥并用作内部对照（即，不加热）。在坐姿时，未加热腿的腘动脉平均剪切率降低（坐前，42.9 +/- 4.5 s（-1）;坐3小时，23.6 +/- 3.3 s（-1）; P < 0.05），但在加热腿中没有（术前38.9 ± 3.4 s（-1）;术后3 h 63.9 ± 16.9 s（-1）; P > 0.05）。坐3小时后，非加热腿的腘动脉血流介导的扩张受损（坐前：7.1 +/- 1.4% vs.坐后：2.8 +/- 0.9%; P < 0.05），但在加热腿中没有受损（坐前：7.3 +/- 1.5% vs.坐后：10.9 +/- 1.8%; P > 0.05）。总的来说，这些数据表明，在长时间坐着局部加热期间防止流动诱导的剪切应力降低可消除腘动脉内皮功能的损害。因此，这些研究结果是一致的假设，坐引起的腿部内皮功能障碍是介导的减少剪切应力。
We and others have recently reported that prolonged sitting impairs endothelial function in the leg vasculature; however, the mechanism(s) remain unknown. Herein, we tested the hypothesis that a sustained reduction in flow-induced shear stress is the underlying mechanism by which sitting induces leg endothelial dysfunction. Specifically, we examined whether preventing the reduction in shear stress during sitting would abolish the detrimental effects of sitting on popliteal artery endothelial function. In 10 young healthy men, bilateral measurements of popliteal artery flow-mediated dilation were performed before and after a 3-h sitting period during which one foot was submerged in 42 degrees C water (i.e., heated) to increase blood flow and thus shear stress, whereas the contralateral leg remained dry and served as internal control (i.e., nonheated). During sitting, popliteal artery mean shear rate was reduced in the nonheated leg (pre-sit, 42.9 +/- 4.5 s(-1); and 3-h sit, 23.6 +/- 3.3 s(-1); P < 0.05) but not in the heated leg (pre-sit, 38.9 +/- 3.4 s(-1); and 3-h sit, 63.9 +/- 16.9 s(-1); P > 0.05). Popliteal artery flow-mediated dilation was impaired after 3 h of sitting in the nonheated leg (pre-sit, 7.1 +/- 1.4% vs. post-sit, 2.8 +/- 0.9%; P < 0.05) but not in the heated leg (pre-sit: 7.3 +/- 1.5% vs. post-sit, 10.9 +/- 1.8%; P > 0.05). Collectively, these data suggest that preventing the reduction of flow-induced shear stress during prolonged sitting with local heating abolishes the impairment in popliteal artery endothelial function. Thus these findings are consistent with the hypothesis that sitting-induced leg endothelial dysfunction is mediated by a reduction in shear stress.