Yamazaki Fumio, Sone Ryoko
Department of Clinical Pathophysiology, School of Health Sciences, University of Occupational and Environmental Health (UOEH), 1-1 Iseigaoka, 807-8555, Yahatanishi-ku, Kitakyushu, Japan.
Eur J Appl Physiol. 2006 Jul;97(5):582-90. doi: 10.1007/s00421-006-0219-4. Epub 2006 Jun 10.
To elucidate the characteristics of vasomotor control in glabrous and nonglabrous skin during dynamic exercise, we compared the vascular responses in both areas to increasing core temperature during the cycle exercise for 30 min at different intensities in the range 20-60% of peak oxygen consumption (VO(2peak)) in a total of 13 male and four female subjects in two experimental protocols. Skin blood flow was monitored using laser Doppler flowmetry. In protocol 1, the slope of the relationship between esophageal temperature (T (es)) and cutaneous vascular conductance (CVC) in the early phase of the exercise decreased (P < 0.05) with increasing exercise intensity at glabrous sites (palm) but not nonglabrous sites (dorsal hand). In protocol 2, to examine whether a difference in vascular responses in the two areas is due to the adrenergic vasoconstrictor system, the release of norepinephrine from adrenergic nerves in forearm and palmar skin was blocked locally by iontophoresis of bretylium tosylate (BT). The administration of BT diminished completely the change of CVC in the palm during the exercise but did not alter the response in the forearm compared with the untreated site. In the two areas, neither the T (es) threshold for vasodilation nor the change in CVC above the threshold in the middle and late phase of the exercise was influenced by the intensity of the exercise. These results suggest that, in the early phase of the exercise, light-to-moderate exercise reduces in an intensity-dependent manner the thermal sensitivity for vasodilation in glabrous skin but not nonglabrous skin via an adrenergic vasoconstrictor pathway.
为了阐明动态运动期间无毛皮肤和有毛皮肤血管运动控制的特征，我们在两个实验方案中，比较了13名男性和4名女性受试者在20-60%峰值耗氧量（VO₂peak）范围内不同强度的30分钟周期运动过程中，这两个区域血管对核心温度升高的反应。使用激光多普勒血流仪监测皮肤血流量。在方案1中，在无毛部位（手掌），随着运动强度增加，运动早期食管温度（T（es））与皮肤血管传导率（CVC）之间关系的斜率降低（P<0.05），而在有毛部位（手背）则没有。在方案2中，为了检查这两个区域血管反应的差异是否归因于肾上腺素能血管收缩系统，通过局部离子电渗法使用溴苄铵（BT）阻断前臂和手掌皮肤肾上腺素能神经中去甲肾上腺素的释放。与未处理部位相比，BT的给药完全消除了运动期间手掌CVC的变化，但未改变前臂的反应。在这两个区域，运动中期和后期血管舒张的T（es）阈值以及高于阈值的CVC变化均不受运动强度的影响。这些结果表明，在运动早期，轻度至中度运动通过肾上腺素能血管收缩途径，以强度依赖的方式降低无毛皮肤而非有毛皮肤血管舒张的热敏感性。
