Department of Movement and Sports Sciences, Ghent University, Watersportlaan 2, Ghent, Belgium.
Eur J Appl Physiol. 2011 Oct;111(10):2571-80. doi: 10.1007/s00421-011-1877-4. Epub 2011 Mar 4.
Carnosine is an abundant dipeptide in human skeletal muscle with proton buffering capacity. There is controversy as to whether training can increase muscle carnosine and thereby provide a mechanism for increased buffering capacity. This study investigated the effects of 5 weeks sprint training combined with a vegetarian or mixed diet on muscle carnosine, carnosine synthase mRNA expression and muscle buffering capacity. Twenty omnivorous subjects participated in a 5 week sprint training intervention (2-3 times per week). They were randomized into a vegetarian and mixed diet group. Measurements (before and after the intervention period) included carnosine content in soleus, gastrocnemius lateralis and tibialis anterior by proton magnetic resonance spectroscopy ((1)H-MRS), true-cut biopsy of the gastrocnemius lateralis to determine in vitro non-bicarbonate muscle buffering capacity, carnosine content (HPLC method) and carnosine synthase (CARNS) mRNA expression and 6 × 6 s repeated sprint ability (RSA) test. There was a significant diet × training interaction in soleus carnosine content, which was non-significantly increased (+11%) with mixed diet and non-significantly decreased (-9%) with vegetarian diet. Carnosine content in other muscles and gastrocnemius buffer capacity were not influenced by training. CARNS mRNA expression was independent of training, but decreased significantly in the vegetarian group. The performance during the RSA test improved by training, without difference between groups. We found a positive correlation (r = 0.517; p = 0.002) between an invasive and non-invasive method for muscle carnosine quantification. In conclusion, this study shows that 5 weeks sprint training has no effect on the muscle carnosine content and carnosine synthase mRNA.
肌肽是人体骨骼肌中丰富的二肽，具有质子缓冲能力。关于训练是否可以增加肌肉肌肽并提供增加缓冲能力的机制存在争议。本研究调查了 5 周短跑训练结合素食或混合饮食对肌肉肌肽、肌肽合酶 mRNA 表达和肌肉缓冲能力的影响。20 名杂食者参与了为期 5 周的短跑训练干预（每周 2-3 次）。他们被随机分为素食者和混合饮食组。测量（干预前后）包括质子磁共振波谱（1H-MRS）测量比目鱼肌、腓肠肌外侧和胫骨前肌中的肌肽含量、腓肠肌外侧的真正切取活检以确定体外非碳酸氢盐肌肉缓冲能力、肌肽含量（HPLC 方法）和肌肽合酶（CARNS）mRNA 表达以及 6×6s 重复冲刺能力（RSA）测试。比目鱼肌肌肽含量存在饮食×训练的显著交互作用，混合饮食时肌肽含量显著增加（+11%），素食饮食时肌肽含量显著降低（-9%）。其他肌肉和腓肠肌缓冲能力不受训练影响。CARNS mRNA 表达与训练无关，但素食组显著降低。RSA 测试期间的表现因训练而提高，组间无差异。我们发现一种侵入性和非侵入性肌肉肌肽定量方法之间存在正相关（r=0.517；p=0.002）。总之，本研究表明，5 周短跑训练对肌肉肌肽含量和肌肽合酶 mRNA 没有影响。
