Cook E A, Taylor P B, Swartman J R
Eur J Appl Physiol Occup Physiol. 1981;47(2):105-11. doi: 10.1007/BF00421662.
To determine the effect of acute exercise and recovery on amino acid incorporation into myocardial protein, female Wistar rats (220-240 g) were exercised to exhaustion by swimming. Animals were sacrificed at exhaustion, or 0.5, 1, 2, 4. or 16 h after exercise. Hearts were removed and perfused for 30 min with a Krebs-Henseleit bicarbonate buffer containing; 15 mM glucose, normal plasma levels of amino acids and 0.1 muCi [3H]-phenylalanine per ml of buffer. Immediately following the exhaustive exercise, amino acid incorporation into extramitochondrial, mitochondrial and whole heart protein was decreased by 50, 55, and 43% respectively. Following 2 h of recovery, incorporation of [3H]-phenylalanine returned to normal in all three protein fractions. No stimulation in protein synthesis was observed in any of the cell fractions. In an attempt to estimate the intracellular availability of [3H]-phenylalanine, the TCA soluble radioactivity was determined. No change from rest was observed at exhaustion or throughout recovery suggesting that the amino acid pool size was not altered. These data indicate that exhaustive exercise temporarily reduces myocardial protein synthesis which quickly returns to normal during recovery.
为了确定急性运动及恢复对氨基酸掺入心肌蛋白的影响，对雌性Wistar大鼠（220 - 240克）进行游泳运动直至疲劳。在运动至疲劳时、运动后0.5、1、2、4或16小时处死动物。取出心脏，用含有15 mM葡萄糖、正常血浆水平氨基酸及每毫升缓冲液含0.1 μCi [3H] - 苯丙氨酸的Krebs - Henseleit碳酸氢盐缓冲液灌注30分钟。在力竭运动后，氨基酸掺入线粒体外、线粒体及全心蛋白的量分别下降了50%、55%和43%。恢复2小时后，[3H] - 苯丙氨酸掺入所有三个蛋白组分的量均恢复正常。在任何细胞组分中均未观察到蛋白质合成受到刺激。为了估计[3H] - 苯丙氨酸在细胞内的可用性，测定了三氯乙酸可溶性放射性。在疲劳时或整个恢复过程中均未观察到与静息状态有变化，这表明氨基酸池大小未改变。这些数据表明，力竭运动会暂时降低心肌蛋白合成，而在恢复过程中其会迅速恢复正常。
