PDF(Pubmed)
Abstract：
A significant increase in circulating cell-free DNA (cfDNA) occurs with physical exercise, which depends on the type of exertion and the duration. The aims of this study were as follows: (1) to investigate the time course of cfDNA and conventional markers of muscle damage from immediately after to 96 h after muscle-damaging exercise; and (2) to investigate the relationship between cfDNA and indicators of primary (low-frequency fatigue and maximal voluntary isometric contraction) and secondary (creatine kinase and delayed-onset muscle soreness) muscle damage in young healthy males. Fourteen participants (age, 22 ± 2 years; weight, 84.4 ± 11.2 kg; height, 184.0 ± 7.4 cm) performed 50 intermittent drop jumps at 20 s intervals. We measured cfDNA and creatine kinase concentrations, maximal voluntary isometric contraction torque, low-frequency fatigue and delayed-onset muscle soreness before and at several time points up to 96 h after exercise. Plasma cfDNA levels increased from immediately postexercise until 72 h postexercise (P < 0.01). Elevation of postexercise cfDNA was correlated with both more pronounced low-frequency fatigue (r = -0.52, P = 3.4 × 10-11) and delayed-onset muscle soreness (r = 0.32, P = 0.00019). Levels of cfDNA change in response to severe primary and secondary muscle damage after exercise. Levels of cfDNA exhibit a stronger correlation with variables related to primary muscle damage than to secondary muscle damage, suggesting that cfDNA is a more sensitive marker of acute loss of muscle function than of secondary inflammation or damaged muscle fibres.
摘要：
随着体育锻炼，循环无细胞DNA（cfDNA）显着增加，这取决于锻炼的类型和持续时间。本研究的目的如下：（1）研究从肌肉破坏性运动后立即到96h的cfDNA和肌肉损伤的常规标记物的时间过程；（2）研究cfDNA与原发性（低频疲劳和最大自愿性等距收缩）和继发性（肌酸激酶和延迟性肌肉酸痛）肌肉损伤指标之间的关系。14名参与者(年龄，22±2年；体重，84.4±11.2kg;高度,184.0±7.4cm）以20s的间隔进行了50次间歇性跌落跳跃。我们测量了cfDNA和肌酸激酶的浓度，最大自愿性等距收缩扭矩，运动前和运动后长达96小时的几个时间点的低频疲劳和延迟性肌肉酸痛。血浆cfDNA水平从运动后立即增加到运动后72小时（P<0.01）。运动后cfDNA的升高与更明显的低频疲劳（r=-0.52，P=3.4×10-11）和延迟性肌肉酸痛（r=0.32，P=0.00019）相关。运动后对严重的原发性和继发性肌肉损伤的cfDNA水平变化。cfDNA水平与原发性肌肉损伤相关变量的相关性强于继发性肌肉损伤，这表明cfDNA是一种比继发性炎症或肌纤维受损更敏感的肌肉功能急性丧失的标志物。
