Effect of acute exercise on citrate synthase activity in untrained and trained human skeletal muscle
Effect of acute exercise on citrate synthase activity in untrained and trained human skeletal muscle
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DOI：
10.1152/ajpregu.2001.280.2.r441
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发表时间：
2001-02-01
影响因子：
2.8
通讯作者：
Richardson, RS
中科院分区：
文献类型：
--
作者：
Leek, BT;Mudaliar, SRD;Richardson, RS
最大柠檬酸合成酶活性（CS）通常被用作骨骼肌有氧能力和线粒体密度的标志。然而，即使使用相似的实验方案和从相同的肌肉中取样，报道的CS也是出了名的变化。运动训练导致CS的增加从0到100%不等。先前有报道称，急性运动可能显著影响CS。为了研究训练中CS的巨大变化受到运动本身改变的影响这一假设，我们研究了人类股外侧肌在训练和未训练时休息和剧烈运动状态下的CS （n = 6）。从四个活检组织（未经训练的休息，未经训练的急性运动，训练的休息和训练的急性运动）中获得的组织用分光光度法分析最大CS。休息状态下的运动训练导致CS增加18.2%（12.3 +/- 0.3至14.5 +/- 0.3 mu mol.min(-1)）。g组织（-1），P <或等于0.05)。然而，急性运动后1小时的增幅更大：在非训练状态下为49.4%（12.3 +/- 0.3至18.3 +/- 0.5 mu mol.min(-1)）。在训练状态（14.5 +/- 0.3 ~ 21.8 +/- 0.4 mu mol.min(-1)）下，P <或等于0.05；g组织（-1），P <或等于0.05)。电镜超微结构分析支持急性运动的影响，运动后1小时发现大量肿胀的线粒体，这可能导致在CS实验中更容易接近CS本身。综上所述，尽管原因不明，但急性运动时CS的增加明显混淆了训练反应，人为地提高了CS值。因此，在测量CS时，相对于最后一次运动阶段的肌肉采样时间是至关重要的，这也解释了之前报道的CS的巨大差异。
Maximal citrate synthase activity (CS) is routinely used as a marker of aerobic capacity and mitochondrial density in skeletal muscle. However, reported CS has been notoriously variable, even with similar experimental protocols and sampling from the same muscles. Exercise training has resulted in increases in CS ranging from 0 to 100%. Previously, it has been reported that acute exercise may significantly affect CS. To investigate the hypothesis that the large variation in CS that occurs with training is influenced by alterations during the exercise itself, we studied CS in human vastus lateralis both in the rested and acutely exercised state while trained and untrained (n = 6). Tissues obtained from four biopsies (untrained rested, untrained acutely exercised, trained rested, and trained acutely exercised) were analyzed spectrophotometrically for maximal CS. Exercise training measured in a rested state resulted in an 18.2% increase in CS (12.3 +/- 0.3 to 14.5 +/- 0.3 mu mol.min(-1).g tissue(-1), P less than or equal to 0.05). However, even greater increases were recorded 1 h after acute exercise: 49.4% in the untrained state (12.3 +/- 0.3 to 18.3 +/- 0.5 mu mol.min(-1).g tissue(-1), P less than or equal to 0.05) and 50.8% in the trained state (14.5 +/- 0.3 to 21.8 +/- 0.4 mu mol.min(-1).g tissue(-1), P less than or equal to 0.05). Ultrastructural analysis, by electron microscopy, supported an effect of acute exercise with the finding of numerous swollen mitochondria 1 h after exercise that may result in greater access to the CS itself in the CS assay. In conclusion, although unexplained, the increased CS with acute exercise can clearly confound training responses and artificially elevate CS values. Therefore, the timing of muscle sampling relative to the last exercise session is critical when measuring CS and offers an explanation for the large variation in CS previously reported.