Ogoh Shigehiko, Nagaoka Ryohei, Mizuno Takamasa, Kimura Shohei, Shidahara Yasuhiro, Ishii Tomomi, Kudoh Michinari, Iwamoto Erika
Department of Biomedical Engineering, Toyo University, Kawagoe-Shi, Saitama, Japan
School of Health Sciences Sapporo Medical University, Sapporo, Hokkaido, Japan.
Physiol Rep. 2016 Dec;4(23). doi: 10.14814/phy2.13046.
Endothelial dysfunction is associated with increased cardiovascular mortality and morbidity; however, this dysfunction may be ameliorated by several therapies. For example, it has been reported that heat-induced increases in blood flow and shear stress enhance endothelium-mediated vasodilator function. Under these backgrounds, we expect that carbon dioxide (CO)-rich water-induced increase in skin blood flow improves endothelium-mediated vasodilation with less heat stress. To test our hypothesis, we measured flow-mediated dilation (FMD) before and after acute immersion of the lower legs and feet in mild warm (38°C) normal or CO-rich tap water (1000 ppm) for 20 min in 12 subjects. Acute immersion of the lower legs and feet in mild warm CO-rich water increased FMD (P < 0.01) despite the lack of change in this parameter upon mild warm normal water immersion. In addition, FMD was positively correlated with change in skin blood flow regardless of conditions (P < 0.01), indicating that an increase in skin blood flow improves endothelial-mediated vasodilator function. Importantly, the temperature of normal tap water must reach approximately 43°C to achieve the same skin blood flow level as that obtained during mild warm CO-rich water immersion (38°C). These findings suggest that CO-rich water-induced large increases in skin blood flow may improve endothelial-mediated vasodilator function while causing less heat stress.
内皮功能障碍与心血管疾病死亡率和发病率的增加有关；然而，这种功能障碍可以通过几种治疗方法得到改善。例如，据报道，热诱导的血流和剪切应力增加可增强内皮介导的血管舒张功能。在这些背景下，我们预计富含二氧化碳（CO）的水引起的皮肤血流增加可在较少热应激的情况下改善内皮介导的血管舒张。为了验证我们的假设，我们对12名受试者的小腿和足部进行急性浸泡，分别浸泡在温和的温水（38°C）普通自来水或富含CO的自来水（1000 ppm）中20分钟，测量浸泡前后的血流介导的血管舒张（FMD）。尽管浸泡在温和的温水普通自来水中时该参数没有变化，但将小腿和足部急性浸泡在温和的富含CO的温水中会增加FMD（P <0.01）。此外，无论何种情况，FMD与皮肤血流变化呈正相关（P <0.01），表明皮肤血流增加可改善内皮介导的血管舒张功能。重要的是，普通自来水的温度必须达到约43°C才能达到与在温和的富含CO的温水浸泡（38°C）期间相同的皮肤血流水平。这些发现表明，富含CO的水引起的皮肤血流大幅增加可能在引起较少热应激的同时改善内皮介导的血管舒张功能。
