Passive heat therapy improves cutaneous microvascular function in sedentary humans via improved nitric oxide-dependent dilation
Passive heat therapy improves cutaneous microvascular function in sedentary humans via improved nitric oxide-dependent dilation
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DOI：
10.1152/japplphysiol.00424.2016
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发表时间：
2016-09-01
影响因子：
3.3
通讯作者：
Minson, Christopher T.
中科院分区：
文献类型：
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作者：
Brunt, Vienna E.;Eymann, Taylor M.;Minson, Christopher T.
被动热疗（反复使用热水浴缸或桑拿浴）可降低心血管风险，但其对微血管功能改善机制的影响还有待研究。我们研究了热疗法对微血管功能的影响，以及是否与皮肤微透析中一氧化氮（NO）生物利用度的变化有关。18名年轻、久坐、其他方面健康的受试者参加了为期8周的热疗（热水浸泡以保持直肠温度>= 38.5 ℃，持续60分钟/疗程; n = 9）或热中性水浸泡（假手术，n = 9），并参与了8- 10年前和8- 10年后的实验，在三个微透析位点评估前臂皮肤充血至39 ℃局部加热的wk干预，所述微透析位点接受1）乳酸林格氏液（对照），2）N-ω-硝基-L-精氨酸（L-NNA;非特异性NO合成酶抑制剂）和3）4-羟基-2，2，6，6-四甲基哌啶-1-氧基（Tempol），一种超氧化物歧化酶模拟物。用于微透析实验的臂始终保持在水外。数据为平均值+/- SE皮肤血管传导性（CVC =激光多普勒流量/平均动脉压），表示为最大CVC百分比（% CVCmax）。热疗法使局部加热平台从42 +/-6% CVCmax增加到53 +/- 6% CVCmax（P < 0.001），并使NO依赖性扩张（对照和L-NNA位点之间的平台差异）从26 +/-6% CVCmax增加到38 +/- 4% CVCmax（P < 0.01），而在假手术组中没有观察到变化。当在0周时汇总所有受试者的数据时，Tempol对局部发热反应没有影响（P = 0.53 vs.对照）。干预期间Tempol研究中心无变化（P = 0.58）。被动热疗通过改善NO依赖性扩张来改善皮肤微血管功能，这可能具有临床意义。
Passive heat therapy (repeated hot tub or sauna use) reduces cardiovascular risk, but its effects on the mechanisms underlying improvements in microvascular function have yet to be studied. We investigated the effects of heat therapy on microvascular function and whether improvements were related to changes in nitric oxide (NO) bioavailability using cutaneous microdialysis. Eighteen young, sedentary, otherwise healthy subjects participated in 8 wk of heat therapy (hot water immersion to maintain rectal temperature >= 38.5 degrees C for 60 min/session; n = 9) or thermoneutral water immersion (sham, n = 9), and participated in experiments before and after the 8-wk intervention in which forearm cutaneous hyperemia to 39 degrees C local heating was assessed at three microdialysis sites receiving 1) Lactated Ringer's (Control), 2) N-omega-nitro- L-arginine (L-NNA; nonspecific NO synthase inhibitor), and 3) 4-hydroxy- 2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol), a superoxide dismutase mimetic. The arm used for microdialysis experiments remained out of the water at all times. Data are means +/- SE cutaneous vascular conductance (CVC = laser Doppler flux/mean arterial pressure), presented as percent maximal CVC (% CVCmax). Heat therapy increased local heating plateau from 42 +/- 6 to 53 +/- 6% CVCmax (P < 0.001) and increased NO-dependent dilation (difference in plateau between Control and L-NNA sites) from 26 +/- 6 to 38 +/- 4% CVCmax (P < 0.01), while no changes were observed in the sham group. When data were pooled across all subjects at 0 wk, Tempol had no effect on the local heating response (P = 0.53 vs. Control). There were no changes at the Tempol site across interventions (P = 0.58). Passive heat therapy improves cutaneous microvascular function by improving NO-dependent dilation, which may have clinical implications.