Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
Scand J Med Sci Sports. 2012 Feb;22(1):24-33. doi: 10.1111/j.1600-0838.2010.01143.x. Epub 2010 Jul 29.
The effects of N-Acetylcysteine (NAC), an unspecific antioxidant, on fatiguing contractile activity-induced injury were investigated. Twenty-four male Wistar rats were randomly assigned to two groups. The placebo group (N=12) received one injection of phosphate buffer (PBS) 1 h prior to contractile activity induced by electrical stimulation. The NAC group (NAC; N=12) received electrical stimulation for the same time period and NAC (500 mg/kg, i.p.) dissolved in PBS 1 h prior to electrical stimulation. The contralateral hindlimb was used as a control, except in the analysis of plasma enzyme activities, when a control group (rats placebo group not electrically stimulated and not treated) was included. The following parameters were measured: tetanic force, muscle fatigue, plasma activities of creatine kinase (CK) and lactate dehydrogenase (LDH), changes in muscle vascular permeability using Evans blue dye (EBD), muscle content of reactive oxygen species (ROS) and thiobarbituric acid-reactive substances (TBARS) and myeloperoxidase (MPO) activity. Muscle fatigue was delayed and tetanic force was preserved in NAC-treated rats. NAC treatment decreased plasma CK and LDH activities. The content of muscle-derived ROS, TBARS, EBD and MPO activity in both gastrocnemius and soleus muscles were also decreased by NAC pre-treatment. Thus, NAC has a protective effect against injury induced by fatiguing contractile activity in skeletal muscle.
本研究旨在探讨 N-乙酰半胱氨酸（NAC）——一种非特异性抗氧化剂，对疲劳性收缩活动诱导损伤的影响。24 只雄性 Wistar 大鼠随机分为两组。安慰剂组（N=12）在收缩活动诱导前 1 小时接受磷酸盐缓冲液（PBS）注射。NAC 组（NAC；N=12）在相同时间内接受电刺激，并在电刺激前 1 小时接受溶解在 PBS 中的 NAC（500mg/kg，腹腔注射）。对侧后肢用作对照，除了在分析血浆酶活性时，包括对照组（未电刺激和未治疗的安慰剂组大鼠）。测量了以下参数：强直力、肌肉疲劳、血浆肌酸激酶（CK）和乳酸脱氢酶（LDH）活性、伊文思蓝染料（EBD）示踪的肌肉血管通透性变化、肌肉活性氧（ROS）和硫代巴比妥酸反应物质（TBARS）含量以及髓过氧化物酶（MPO）活性。NAC 处理延迟了肌肉疲劳，并保持了强直力。NAC 治疗降低了血浆 CK 和 LDH 活性。NAC 预处理还降低了腓肠肌和比目鱼肌的肌肉源性 ROS、TBARS、EBD 和 MPO 活性。因此，NAC 对骨骼肌疲劳性收缩活动诱导的损伤具有保护作用。
