Physiology, Australian Institute of Sport, Bruce, Australian Capital Territory, Australia.
J Sci Med Sport. 2013 Jan;16(1):82-5. doi: 10.1016/j.jsams.2012.05.006. Epub 2012 Jul 12.
We tested the hypothesis that fast skeletal muscle troponin I (fsTnI) concentration in serum would increase more than those of slow skeletal muscle troponin I (ssTnI) after eccentric exercise of the elbow flexors using a sensitive blood marker to track fibre specific muscle damage.
Observational comparison of response in a single experimental group.
Eight young men (26.4±6.2 years) performed 210 (35 sets of 6) eccentric contractions of the elbow flexors on an isokinetic dynamometer with one arm. Changes in serum fsTnI and ssTnI concentrations, serum creatine kinase (CK) activity, and maximal voluntary isometric contraction torque (MVIC) before and 1, 2, 3, 4 and 14 days following exercise were analysed by a Student-Newman-Keuls multiple comparison test. The relationship between serum CK activity and fsTnI or ssTnI concentrations was determined using a Pearson's product moment correlation.
Significant (P<0.05) decreases in MVIC and increases in serum CK activity and fsTnI were evident after exercise, but ssTnI did not change. The time course of changes in fsTnI was similar to that of CK, peaking at 4 days post-exercise, and the two were highly correlated (r=0.8).
Increases in serum fsTnI concentrations reflect muscle damage, and it seems likely that only fast twitch fibres were damaged by eccentric contractions.
我们使用一种敏感的血液标志物来跟踪纤维特异性肌肉损伤，检验血清中快肌肌钙蛋白 I（fsTnI）浓度在离心性肘屈肌运动后比慢肌肌钙蛋白 I（ssTnI）增加更多的假设。
在单个实验组中观察比较反应。
8 名年轻男性（26.4±6.2 岁）用等速测力仪对一侧手臂进行 210 次（35 组，每组 6 次）离心性肘屈肌收缩。运动前后及运动后 1、2、3、4 和 14 天，通过学生-纽曼-凯斯多因素比较检验分析血清 fsTnI 和 ssTnI 浓度、血清肌酸激酶（CK）活性和最大自主等长收缩扭矩（MVIC）的变化。采用 Pearson 积矩相关分析确定血清 CK 活性与 fsTnI 或 ssTnI 浓度之间的关系。
运动后 MVIC 明显下降（P<0.05），血清 CK 活性和 fsTnI 升高，但 ssTnI 没有变化。fsTnI 的变化时间过程与 CK 相似，在运动后 4 天达到峰值，两者高度相关（r=0.8）。
血清 fsTnI 浓度的增加反映了肌肉损伤，似乎只有快肌纤维受到离心性收缩的损伤。
