Décombaz J, Reinhardt P, Anantharaman K, von Glutz G, Poortmans J R
Eur J Appl Physiol Occup Physiol. 1979 Apr 12;41(1):61-72. doi: 10.1007/BF00424469.
Free amino acids, urea, and creatinine were analyzed in venous blood and urine of 11 trained (28--81 years old) male subjects before, immediately after, and 1 day after a 100 km running competition. The urinary excretion per minute of all amino acids was lowered after the contest. The renal clearance of creatinine was reduced from 116 to 60 ml/min and the clearance of most amino acids was reduced to a similar extent. However, for the amino acids with a resting clearance under 1 ml/min (x), a high relative clearance ratio (y in % of x) was seen post-exercise: y = -92.3 (log10 x) +23.1, r = -0.83, showing that their high reabsorption capacity had been impaired. Serum concentrations of most free amino acids, including the branched-chain amino acids and alanine, were reduced to 35--85% of the pre-race values. The sulfur amino acids were elevated either at the end of (cystine, to 180%) or 24 h after (methionine, to 155%) the race. Urea production increased by 44% while creatinine production tended to decrease. The production of 3-methylhistidine remained unchanged. These findings are compatible with a stimulation of gluconegenesis at the expense of the amino acid pool without induction of muscle protein catabolism.
对11名训练有素的（28 - 81岁）男性受试者在100公里跑步比赛前、比赛刚结束后以及比赛后1天的静脉血和尿液中的游离氨基酸、尿素和肌酐进行了分析。比赛后所有氨基酸的每分钟尿排泄量均降低。肌酐的肾清除率从116降至60 ml/分钟，大多数氨基酸的清除率也降低到类似程度。然而，对于静息清除率低于1 ml/分钟（x）的氨基酸，运动后出现了较高的相对清除率（y，以x的百分比表示）：y = -92.3（log10 x）+23.1，r = -0.83，表明它们的高重吸收能力受到了损害。大多数游离氨基酸的血清浓度，包括支链氨基酸和丙氨酸，降至赛前值的35 - 85%。含硫氨基酸在比赛结束时（胱氨酸，升至180%）或比赛后24小时（蛋氨酸，升至155%）升高。尿素生成增加了44%，而肌酐生成则趋于减少。3 - 甲基组氨酸的生成保持不变。这些发现与以氨基酸池为代价刺激糖异生而不诱导肌肉蛋白分解代谢是一致的。
