Acute heat exposure improves microvascular function in skeletal muscle of aged adults.
Acute heat exposure improves microvascular function in skeletal muscle of aged adults.
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急性热暴露可改善老年人骨骼肌的微血管功能。
DOI：
10.1152/ajpheart.00645.2021
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Romero,StevenA
中科院分区：
文献类型：
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作者：
Richey,RauchelleE;Hemingway,HoldenW;Moore,AmyM;Olivencia-Yurvati,AlbertH;Romero,StevenA
急性热暴露改善微血管功能的老年人评估使用反应性充血。皮肤和骨骼肌微循环被认为有助于这种反应，但由于在这些血管床之间区分血流的方法上存在挑战，这一点从未得到证实。我们假设急性热水浸泡可以改善健康老年人股外侧肌微循环中的内皮依赖型血管舒张，而不是内皮依赖型血管舒张。参与者（70±5岁）在热中性（36°C）或热（40°C）水中浸泡60分钟。浸泡90分钟后，骨骼肌微透析绕过皮肤循环，通过测量乙酰胆碱（ACh， 27.5和55.0 mM）和硝普钠（SNP， 21和42 mM）分级输注后的局部充血反应，直接评估内皮依赖性和内皮非依赖性血管舒张。对27.5 mM乙酰氨基酚的充血反应在不同的热条件下没有差异（P= 0.9）。然而，先前热水浸泡对55.0 mM乙酰胆碱的充血反应增加（热中性浸泡，43.9±23.2 mL/min/100 g比热水浸泡，66.5±25.5 mL/min/100 g；P< 0.01）。同样，在不同的热条件下，21 mM SNP的血凝反应没有差异（P= 0.3），但在42 mM SNP的热水浸泡后，血凝反应增加（热中性浸泡，48.8±25.6 mL/min/100 g vs热水浸泡，90.7±53.5 mL/min/100 g；P< 0.01）。这些数据表明，急性热暴露可改善老年人骨骼肌微血管功能。急性热暴露改善老年人微血管功能，用反应性充血进行评估。皮肤和骨骼肌微循环被认为有助于这种反应，但由于在这些血管床之间区分血流的方法上存在挑战，这一点从未得到证实。利用微透析技术绕过皮肤循环，我们证明了热暴露改善了老年人骨骼肌微循环中内皮依赖性和内皮非依赖性血管舒张。
Acute heat exposure improves microvascular function in aged adults as assessed using reactive hyperemia. The cutaneous and skeletal muscle microcirculations are thought to contribute to this response, but this has never been confirmed due to the methodological challenges associated with differentiating blood flow between these vascular beds. We hypothesized that acute hot water immersion would improve endothelial-dependent, but not endothelial-independent vasodilation in the microcirculation of the vastus lateralis muscle in healthy aged adults. Participants (70 ± 5 yr) were immersed for 60 min in thermoneutral (36°C) or hot (40°C) water. Ninety minutes following immersion, skeletal muscle microdialysis was used to bypass the cutaneous circulation and directly assess endothelial-dependent and endothelial-independent vasodilation by measuring the local hyperemic response to graded infusions of acetylcholine (ACh, 27.5 and 55.0 mM) and sodium nitroprusside (SNP, 21 and 42 mM), respectively. The hyperemic response to 27.5 mM ACh did not differ between thermal conditions (P= 0.9). However, the hyperemic response to 55.0 mM ACh was increased with prior hot water immersion (thermoneutral immersion, 43.9 ± 23.2 mL/min/100 g vs. hot water immersion, 66.5 ± 25.5 mL/min/100 g;P< 0.01). Similarly, the hyperemic response to 21 mM SNP did not differ between thermal conditions (P= 0.3) but was increased following hot water immersion with the infusion of 42 mM SNP (thermoneutral immersion, 48.8 ± 25.6 mL/min/100 g vs. hot water immersion, 90.7 ± 53.5 mL/min/100 g;P< 0.01). These data suggest that acute heat exposure improves microvascular function in skeletal muscle of aged humans.NEW & NOTEWORTHYAcute heat exposure improves microvascular function in aged adults as assessed using reactive hyperemia. The cutaneous and skeletal muscle microcirculations are thought to contribute to this response, but this has never been confirmed due to the methodological challenges associated with differentiating blood flow between these vascular beds. Using the microdialysis technique to bypass the cutaneous circulation, we demonstrated that heat exposure improves endothelial-dependent and endothelial-independent vasodilation in the microcirculation of skeletal muscle in aged humans.