Purpose: To determine sex-related differences in the skin blood flow (SkBF) response to exercise, local heating, and acetylcholine (ACh) in children, and to assess nitric oxide contribution to the SkBF response. Methods: Forearm SkBF during local heating (44°C), ACh iontophoresis, and exercise (30-min cycling and 60% of maximum oxygen consumption) was assessed, using laser Doppler fluxmetry, in 12 boys and 12 girls (7–13 y old), with and without nitric oxide synthase inhibition, using N^ω-nitro-L-arginine methyl ester iontophoresis. Results: Local-heating-induced and ACh-induced SkBF increase were not different between boys and girls (local heating: 1445% [900%] and 1432% [582%] of baseline, P = .57; ACh: 673% [434%] and 558% [405%] of baseline, respectively, P = .18). Exercise-induced increase in SkBF was greater in boys than girls (528% [290%] and 374% [192%] of baseline, respectively, P = .03). N^ω-nitro-L-arginine methyl ester blunted the SkBF response to ACh and during exercise (P < .001), with no difference between sexes. Conclusion: SkBF responses to ACh and local heat stimuli were similar in boys and girls, while the increase in SkBF during exercise was greater in boys. The apparent role of nitric oxide was not different between boys and girls. It is suggested that the greater SkBF response in boys during exercise was related to greater relative heat production and dissipation needs at this exercise intensity. The response to body size-related workload should be further examined.

目的：确定儿童对运动、局部加热和乙酰胆碱 (ACh) 的皮肤血流量 (SkBF) 反应的性别相关差异，并评估一氧化氮对 SkBF 反应的贡献。方法：使用激光多普勒通量测定法对 12 名男孩和 12 名女孩（7-13 岁）进行局部加热（44°C）、ACh 离子电渗疗法和运动（30 分钟自行车和 60% 最大耗氧量）期间的前臂 SkBF旧），有和没有一氧化氮合酶抑制，使用 N ^ω -硝基-L-精氨酸甲酯离子电渗疗法。结果：男孩和女孩之间局部加热引起的和 ACh 引起的 SkBF 增加没有差异（局部加热：基线的 1445% [900%] 和 1432% [582%]， P = .57; ACh：分别为基线的 673% [434%] 和 558% [405%]，P  = .18)。男孩运动引起的 SkBF 增加大于女孩（分别为基线的 528% [290%] 和 374% [192%]，P  = .03）。N ^ω -硝基-L-精氨酸甲酯减弱了 SkBF 对 ACh 和运动期间的反应 ( P  < .001)，两性之间没有差异。结论：男孩和女孩对 ACh 和局部热刺激的 SkBF 反应相似，而男孩在运动期间 SkBF 的增加更大。一氧化氮的明显作用在男孩和女孩之间没有区别。这表明男孩在运动期间更大的 SkBF 反应与在该运动强度下更大的相对热量产生和消散需求有关。应进一步检查对与体型相关的工作量的反应。