We assessed endothelial function by flow-mediated dilatation (FMD), levels of the NO-precursor L-arginine, and markers of endothelial inflammation before, at the finish line, and one week after the Norseman Xtreme triathlon. The race is an Ironman distance triathlon with a total elevation of 5200 m. Nine male participants were included. They completed the race in 14.5 (13.4–15.3) hours. FMD was significantly reduced to 3.1 (2.1–5.0)% dilatation compared to 8.7 (8.2–9.3)% dilatation before the race (p < 0.05) and was normalized one week after the race. L-arginine showed significantly reduced levels at the finish line (p < 0.05) but was normalized one week after the race. Markers of endothelial inflammation E-Selectin, VCAM-1, and ICAM-1 all showed a pattern with increased values at the finish line compared to before the race (all p < 0.05), with normalization one week after the race. In conclusion, we found acutely reduced FMD with reduced L-arginine levels and increased E-Selectin, VCAM-1, and ICAM-1 immediately after the Norseman Xtreme triathlon. Our findings indicate a transient reduced endothelial function, measured by the FMD-response, after prolonged strenuous exercise that could be explained by reduced NO-precursor L-arginine levels and increased endothelial inflammation.

中文翻译：

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长期剧烈运动后 FMD 反应和 L-精氨酸的短暂降低伴随着 E-选择素、VCAM 和 ICAM 水平的增加

我们通过流量介导的扩张 (FMD)、NO 前体 L-精氨酸的水平和内皮炎症标志物评估了内皮功能，在 Norseman Xtreme 铁人三项赛之前、终点线和一周后。比赛为铁人三项，总海拔5200米。包括九名男性参与者。他们在 14.5 (13.4–15.3) 小时内完成了比赛。与赛前 8.7 (8.2-9.3)% 的扩张相比，FMD 显着降低至 3.1 (2.1-5.0)% 的扩张（p < 0.05），并在赛后一周恢复正常。L-精氨酸在终点线的水平显着降低（p< 0.05) 但在比赛后一周被归一化。内皮炎症的标记物 E-Selectin、VCAM-1 和 ICAM-1 都显示出一种模式，与比赛前相比，终点线的值增加（所有p < 0.05），比赛后一周恢复正常。总之，我们发现在 Norseman Xtreme 铁人三项之后立即 FMD 急剧减少，L-精氨酸水平降低，E-选择素、VCAM-1 和 ICAM-1 增加。我们的研究结果表明，在长时间剧烈运动后，通过 FMD 反应测量的内皮功能暂时降低，这可以通过降低 NO 前体 L-精氨酸水平和增加内皮炎症来解释。