不同训练强度对血浆游离DNA的影响

目的:观察不同训练强度对运动员血浆游离DNA(cf-DNA)的影响并探讨其可能机制,以期为运动训练负荷监控提供新型标志物。方法:60名田径运动员随机分为三组:低强度训练组,中强度训练组和高强度训练组,在标准400 m跑道上,分别进行60%、75%和90%HRmax(最大心率)强度训练(跑步)20 min,测定训练前后cf-DNA、外周血淋巴细胞凋亡率、淋巴细胞促凋亡因子(Bax)和抗凋亡因子(Bcl-2)蛋白的表达。结果:低强度训练组和中强度训练组各指标在训练前后均无显著性变化。高强度训练组训练后即刻,cf-DNA升高了110.0%(102.23±21.37 pg/μL vs 48.67±12.72 pg/μL,P<0.01),淋巴细胞凋亡率升高了72.5%(7.16±1.05%vs 4.15±0.55%,P<0.01),Bax/Bcl-2比值升高了82.6%(0.42±0.10 vs0.23±0.07,P<0.01)。结论:cf-DNA具有训练强度依赖性,可能是运动训练负荷监控与组织损伤早期、敏感的新型标志物;外周血淋巴细胞凋亡参与了高强度训练后cf-DNA的升高。

Effects of Different Training Intensity on Cell-free Plasma DNA

The present study aimed to investigate the effects of different training intensity on cell-free plasma DNA(cf-DNA)in athletes and its possible mechanism in order to provide a novel marker of load supervision in exercise training.Sixty track and field athletes who were randomly divided into three groups:low intensity training group,moderate intensity training group and high intensity training group conducted different training(running)intensity at 60%,75% and 90%HRmax(maximal heart rate)for 20 minutes respectively on 400m track.Cf-DNA,apoptotic rate of peripheral blood lymphocytes,pro-apoptotic protein(Bax)and anti-apoptotic protein(Bcl-2)expression in peripheral blood lymphocytes were determined pre-and immediate post-training.Results:No statistically changes were noted in all the indicators in low intensity training group and moderate intensity training group.In contrast,af ter high intensity training,cf-DNA increased by 110.0%(102.23±21.37pg/μL vs 48.67±12.72pg/μL,P<0.01),apoptotic rate of peripheral blood lymphocytes increased by 72.5%(7.16±1.05% vs 4.15±0.55%,P<0.01)and Bax/ Bcl-2 ratio increased by 82.6%(0.42±0.10 vs 0.23±0.07,P<0.01).Conclusion:Cf-DNA was dependent on train ing intensity,which maybe an early sensitive novel marker for load supervision and tissue damage in exercise train ing;apoptosis of peripheral blood lymphocytes could participate in the process of high intensity training induced cf-DNA raise.