Pereira Bruno Cesar, Pauli José Rodrigo, Antunes Lusânia Maria Greggi, de Freitas Ellen Cristini, de Almeida Mara Ribeiro, de Paula Venâncio Vinícius, Ropelle Eduardo Rochete, de Souza Claudio Teodoro, Cintra Dennys Esper, Papoti Marcelo, da Silva Adelino Sanchez Ramos
Universidade de São Paulo (USP), Escola de Educação Física e Esporte de Ribeirão Preto (EEFERP), Ribeirão Preto, São Paulo, Brasil.
BMC Physiol. 2013 Oct 8;13:11. doi: 10.1186/1472-6793-13-11.
The alkaline version of the single-cell gel (comet) assay is a useful method for quantifying DNA damage. Although some studies on chronic and acute effects of exercise on DNA damage measured by the comet assay have been performed, it is unknown if an aerobic training protocol with intensity, volume, and load clearly defined will improve performance without leading to peripheral blood cell DNA damage. In addition, the effects of overtraining on DNA damage are unknown. Therefore, this study aimed to examine the effects of aerobic training and overtraining on DNA damage in peripheral blood and skeletal muscle cells in Swiss mice. To examine possible changes in these parameters with oxidative stress, we measured reduced glutathione (GSH) levels in total blood, and GSH levels and lipid peroxidation in muscle samples.
Performance evaluations (i.e., incremental load and exhaustive tests) showed significant intra and inter-group differences. The overtrained (OTR) group showed a significant increase in the percentage of DNA in the tail compared with the control (C) and trained (TR) groups. GSH levels were significantly lower in the OTR group than in the C and TR groups. The OTR group had significantly higher lipid peroxidation levels compared with the C and TR groups.
Aerobic and anaerobic performance parameters can be improved in training at maximal lactate steady state during 8 weeks without leading to DNA damage in peripheral blood and skeletal muscle cells or to oxidative stress in skeletal muscle cells. However, overtraining induced by downhill running training sessions is associated with DNA damage in peripheral blood and skeletal muscle cells, and with oxidative stress in skeletal muscle cells and total blood.
单细胞凝胶（彗星）试验的碱性版本是一种用于量化DNA损伤的有用方法。尽管已经进行了一些关于运动对通过彗星试验测量的DNA损伤的慢性和急性影响的研究，但尚不清楚强度、量和负荷明确界定的有氧训练方案是否能在不导致外周血细胞DNA损伤的情况下提高运动表现。此外，过度训练对DNA损伤的影响尚不清楚。因此，本研究旨在探讨有氧训练和过度训练对瑞士小鼠外周血和骨骼肌细胞DNA损伤的影响。为了研究这些参数随氧化应激可能发生的变化，我们测量了全血中还原型谷胱甘肽（GSH）水平，以及肌肉样本中的GSH水平和脂质过氧化。
性能评估（即递增负荷和力竭试验）显示组内和组间存在显著差异。与对照组（C）和训练组（TR）相比，过度训练（OTR）组尾部DNA百分比显著增加。OTR组的GSH水平显著低于C组和TR组。与C组和TR组相比，OTR组的脂质过氧化水平显著更高。
在8周的最大乳酸稳态训练中，有氧和无氧运动表现参数可以得到改善，而不会导致外周血和骨骼肌细胞的DNA损伤或骨骼肌细胞的氧化应激。然而，下坡跑训练导致的过度训练与外周血和骨骼肌细胞的DNA损伤以及骨骼肌细胞和全血的氧化应激有关。
