Hellsten-Westing Y, Kaijser L, Ekblom B, Sjödin B
Department of Physiology III, Karolinska Institute, Stockholm, Sweden.
Am J Physiol. 1994 Jan;266(1 Pt 2):R81-6. doi: 10.1152/ajpregu.1994.266.1.R81.
The exchange of purines in liver and active skeletal muscle with short-term exhaustive exercise was investigated. Eight male subjects performed two similar 10-min bouts of exhaustive supine cycling, separated by 75 min of rest. Immediately after termination of the second bout, a tourniquet was applied to the upper part of the thigh for 10 min. After the first bout, the arterial concentration of hypoxanthine and uric acid increased from 4.1 +/- 0.3 (SE) to a peak value of 36.3 +/- 7.9 mumol/l (P < 0.05) and from 335 +/- 23 to a peak value of 421 +/- 28 mumol/l (P < 0.05), respectively. There was a net release of hypoxanthine from the muscle at 12 and 45 min postexercise and an uptake of hypoxanthine and inosine in the liver at 7 and 42 min postexercise. Uric acid was released from the liver at 7 and 42 min after exercise. Before the second exercise bout and at 2 and 10 min after the release of the tourniquet, there was a significant net uptake of uric acid by the muscle. The present study demonstrates that, after strenuous short-term exercise, the main source of plasma hypoxanthine is the muscle, with no net contribution of this purine from the liver. Hypoxanthine in the blood is taken up by the liver where most of it is converted to uric acid. After exercise and a short period of ischemia, uric acid is taken up by the muscle.
研究了短期力竭运动后肝脏和活跃骨骼肌中嘌呤的交换情况。八名男性受试者进行了两次类似的10分钟仰卧力竭骑行，中间休息75分钟。在第二次骑行结束后立即在大腿上部使用止血带10分钟。第一次骑行后，次黄嘌呤和尿酸的动脉浓度分别从4.1±0.3（标准误）升至峰值36.3±7.9μmol/L（P<0.05）和从335±23升至峰值421±28μmol/L（P<0.05）。运动后12分钟和45分钟肌肉有次黄嘌呤净释放，运动后7分钟和42分钟肝脏有次黄嘌呤和肌苷摄取。运动后7分钟和42分钟肝脏释放尿酸。在第二次运动前以及止血带松开后2分钟和10分钟，肌肉有显著的尿酸净摄取。本研究表明，剧烈短期运动后，血浆次黄嘌呤的主要来源是肌肉，肝脏对这种嘌呤无净贡献。血液中的次黄嘌呤被肝脏摄取，其中大部分在肝脏中转化为尿酸。运动和短期缺血后，尿酸被肌肉摄取。
