Department of Sport Research, Japan Institute of Sports Sciences, Tokyo, Japan.
Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan.
J Sports Sci. 2021 Jul;39(13):1437-1444. doi: 10.1080/02640414.2021.1876329. Epub 2021 Mar 16.
We aimed to evaluate whether changes in the noninvasively assessed urinary N-terminal fragment of titin (U-titin) concentration may be associated with those of serum creatine kinase (CK) activity, transverse relaxation time (T), maximal voluntary contraction (MVC) torque, range of motion (ROM), and muscle soreness, following high-intensity eccentric exercise. Twenty-eight healthy young men performed 30 maximal isokinetic (120°/s) eccentric elbow flexor contractions using an isokinetic dynamometer. U-titin concentration, serum CK activity, T, MVC torque, ROM, and muscle soreness were measured before and after a maximum of 4 days. Both U-titin concentration and serum CK activity increased post-exercise in a similar manner, though the former elevated slightly earlier (p < 0.05). The peak values of log U-titin concentration following eccentric exercise were strongly correlated with those of log serum CK activity (r = 0.90, p < 0.05) and T (r = 0.84, p < 0.05). There were moderate correlations between peak values of U-titin concentration and those of MVC torque (r = 0.69, p < 0.05) and ROM decline rate (r = 0.45, p < 0.05). These results suggest that in healthy young men, the non-invasive marker, U-titin, may be used as a serum CK surrogate following exercise-induced severe muscle damage.
我们旨在评估在高强度离心运动后，非侵入性评估的肌联蛋白尿 N 端片段（U-肌联蛋白）浓度的变化是否与血清肌酸激酶（CK）活性、横向弛豫时间（T）、最大自主收缩（MVC）扭矩、运动范围（ROM）和肌肉酸痛的变化相关。28 名健康年轻男性使用等速测力计进行了 30 次最大等速（120°/s）离心肘屈肌收缩。在最大 4 天内，分别在运动前后测量 U-肌联蛋白浓度、血清 CK 活性、T、MVC 扭矩、ROM 和肌肉酸痛。运动后 U-肌联蛋白浓度和血清 CK 活性均以相似的方式升高，但前者升高稍早（p < 0.05）。离心运动后 U-肌联蛋白浓度的峰值与血清 CK 活性（r = 0.90，p < 0.05）和 T（r = 0.84，p < 0.05）的峰值呈强相关。U-肌联蛋白浓度的峰值与 MVC 扭矩（r = 0.69，p < 0.05）和 ROM 下降率（r = 0.45，p < 0.05）呈中度相关。这些结果表明，在健康年轻男性中，非侵入性标志物 U-肌联蛋白可作为运动引起的严重肌肉损伤后血清 CK 的替代物。
