Background Athletes are increasingly exploring ways to enhance their physical performance. Increasing blood flow to the working tissues through endothelium-dependent vasodilation is one factor athletes use to realize these results. Sports supplements such as pre-workouts tout this benefit; however, many have not been tested under laboratory conditions to examine the effects of commonly used supplements on vasodilation. Two popular supplements are Nitrosigine® and citrulline malate (CM). Thus, the purpose of this experiment was to determine the effects of Nitrosigine and CM on vasodilation using ultrasound and flow mediated dilation (FMD). Methods Healthy, normotensive, and physically active male ( n = 16) and female ( n = 8) young adults participated in the present investigation. We utilized a randomized, double-blind, within-subjects design where participants reported for three trials, each preceded by a 7-day washout period. Baseline FMD measurement was obtained for each visit, followed by consumption of one clinical dose CM (8 g), Nitrosigine (1.5 g), or dextrose placebo (8 g). Following a 60-min digestion period, FMD was repeated. Supplementation order was randomized controlling for potential order effects. Results Repeated measures ANOVA yielded a significant supplement (3) x time (2) effect ( p < .001), such that Nitrosigine and CM yielded a greater improvement in FMD response than placebo. After supplementation, Nitrosigine and CM increased FMD by 31 and 34%, respectively, compared to a decrease of 2% during the placebo trial. After allometric scaling of the FMD values, supplement x time effect remained significant ( p = .001) and changes were similar to non-scaled results. Nitrosigine (23%) and CM (25%) generated significantly greater allometric scaled FMD values when compared to the placebo trial (0.60%). Discussion Both Nitrisigine and CM increased endothelial-dependent vasodilation as measured by a change in FMD. Increased vasodilation leads to an increase in skeletal muscle blood flow resulting in potential improvements in exercise performance.

中文翻译：

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Nitrosigine® 和瓜氨酸马来酸盐对血管舒张的急性作用

背景 运动员越来越多地探索提高身体表现的方法。通过内皮依赖性血管舒张增加流向工作组织的血流量是运动员用来实现这些结果的一个因素。运动补充剂（如锻炼前）吹捧这种好处；然而，许多尚未在实验室条件下进行测试，以检查常用补充剂对血管舒张的影响。两种流行的补充剂是 Nitrosigine® 和瓜氨酸苹果酸盐 (CM)。因此，本实验的目的是使用超声和流量介导的扩张 (FMD) 来确定亚硝基辛和 CM 对血管舒张的影响。方法健康、血压正常、身体活跃的男性（n = 16）和女性（n = 8）年轻人参与了本次调查。我们使用了随机、双盲、受试者内设计，参与者报告了三个试验，每个试验之前都有 7 天的清除期。每次就诊都获得基线 FMD 测量值，然后服用一种临床剂量的 CM（8 克）、硝基西嗪（1.5 克）或葡萄糖安慰剂（8 克）。在 60 分钟的消化期后，重复 FMD。补充顺序是随机控制的潜在顺序效应。结果重复测量方差分析产生了显着的补充 (3) x 时间 (2) 效应 (p < .001)，因此 Nitrosigine 和 CM 比安慰剂在 FMD 反应方面产生了更大的改善。补充后，Nitrosigine 和 CM 分别使 FMD 增加了 31% 和 34%，而安慰剂试验期间减少了 2%。在对 FMD 值进行异速缩放后，补充剂 x 时间效应仍然显着（p = . 001) 并且变化与非标度结果相似。与安慰剂试验 (0.60%) 相比，Nitrosigine (23%) 和 CM (25%) 产生了显着更高的异速生长 FMD 值。讨论 Nitrisigine 和 CM 都增加了内皮依赖性血管舒张，这是通过 FMD 的变化来衡量的。血管舒张增加导致骨骼肌血流量增加，从而可能改善运动表现。