Graduate School of Sport Sciences, Waseda University, Saitama, Japan.
Faculty of Sport Sciences, Waseda University, Saitama, Japan.
J Sports Sci Med. 2020 Feb 24;19(1):121-129. eCollection 2020 Mar.
We aimed to compare the urinary titin N-terminal fragment (UTF) concentration after concentric and eccentric exercise and to clarify the specific response of UTF to exercise-induced muscle damage (EIMD). Nine healthy young men performed 30 concentric elbow flexion exercises with maximum effort, rested for at least eight weeks, and performed eccentric exercises at the same workload using the same arm. Changes in the maximal voluntary isometric contraction (MVIC), muscle soreness (SOR), range of motion (ROM), serum creatine kinase (CK) activity, and UTF concentrations were recorded before and after for six consecutive days after exercise. There was no significant difference in workload during exercise between the two exercise types. However, serum CK activity increased after eccentric exercise (p < 0.05). Additionally, MVIC, SOR, ROM, and UTF concentration were significantly higher after eccentric exercise than after concentric exercise (p < 0.05). Although workload was the same, the UTF concentration greatly increased after eccentric exercise. Based on these results, we suggest that UTF can be a non-invasive and highly specific biomarker of EIMD.
我们旨在比较向心性和离心性运动后尿肌钙蛋白 N 端片段（UTF）的浓度，并阐明 UTF 对运动诱导的肌肉损伤（EIMD）的特定反应。9 名健康年轻男性用尽全力进行 30 次向心性肘屈伸运动，至少休息 8 周，然后用同一只手臂以相同的工作量进行离心运动。在运动后的连续 6 天内，记录最大自主等长收缩（MVIC）、肌肉酸痛（SOR）、关节活动度（ROM）、血清肌酸激酶（CK）活性和 UTF 浓度的变化。两种运动类型的运动过程中的工作量没有显著差异。然而，离心运动后血清 CK 活性增加（p < 0.05）。此外，离心运动后 MVIC、SOR、ROM 和 UTF 浓度均明显高于向心性运动（p < 0.05）。尽管工作量相同，但离心运动后 UTF 浓度大大增加。基于这些结果，我们认为 UTF 可以作为 EIMD 的一种非侵入性和高度特异性的生物标志物。
