Hochachka P W, Dressendorfer R H
Eur J Appl Physiol Occup Physiol. 1976 Sep 23;35(4):235-42. doi: 10.1007/BF00423282.
It has been demonstrated in several diving vertebrates that succinate, a component of the Krebs cycle, accumulates in blood during breath-hold dives. The production of succinate is thought to result from amino acid catabolism. Our purpose was to determine whether succinate accumulation occurs in man during muscular activity requiring anaerobic energy contribution. Experiments using an endurance athlete included apneic work on an underwater ergometer and treadmill running to exhaustion. During 1 min breath-hold "dives" in cold water while exercising at a work rate equivalent to 62% of VO2max, venous succinate increased from 42 mumoles/l (M X 10(-6)) at rest to 125 M X 10(-6). The treadmill run elicited VO2max and increased succinate from a similar resting value to 93 M X 10(-6). Increases in alanine, lactate, and pyruvate were observed for both types of exercise. The findings confirm that succinate accumulation also occurs in man. It was suggested that amino acid catabolism may provide a source of anaerobic energy production in addition to glycolysis. However, the importance of the proposed energy pathway remains to be quantified.
在几种潜水脊椎动物中已证实，三羧酸循环的组成部分琥珀酸在屏气潜水时会在血液中积累。琥珀酸的产生被认为是氨基酸分解代谢的结果。我们的目的是确定在需要无氧能量供应的肌肉活动期间，人体是否会发生琥珀酸积累。对一名耐力运动员进行的实验包括在水下测力计上进行屏气运动以及在跑步机上跑步直至力竭。在冷水环境中以相当于最大摄氧量（VO2max）62%的工作强度进行1分钟屏气“潜水”运动时，静脉血中琥珀酸浓度从静息时的42微摩尔/升（M×10⁻⁶）增加到125M×10⁻⁶。跑步机跑步达到最大摄氧量（VO2max），琥珀酸浓度从相似的静息值增加到93M×10⁻⁶。两种运动类型均观察到丙氨酸、乳酸和丙酮酸增加。这些发现证实人体也会发生琥珀酸积累。有人提出，除了糖酵解外，氨基酸分解代谢可能为无氧能量产生提供一个来源。然而，所提出的能量途径的重要性仍有待量化。
