Shimomura Y, Suzuki T, Saitoh S, Tasaki Y, Harris R A, Suzuki M
Institute of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan.
J Appl Physiol (1985). 1990 Jan;68(1):161-5. doi: 10.1152/jappl.1990.68.1.161.
The effect of exercise on the activity of branched-chain alpha-keto acid dehydrogenase complex in liver and muscle was studied in rats fed a high-fat (FAT) or a high-carbohydrate (CHO) diet. Both diet groups of rats were offered isoenergetic diets by a meal-feeding method and were trained by treadmill running. On the final day of the experiment, half of the rats in each diet group were exercised by 2 h of running just before they were killed. The activity state of the enzyme complex was elevated maximally by exercise in liver of rats fed the FAT diet but not in liver of rats fed the CHO diet, suggesting that catabolism of branched-chain amino acids in rat liver during exercise was enhanced by the FAT diet. The activity state of the enzyme complex in muscle was enhanced by exercise in both groups of rats, but a significant difference was not observed between the groups. The concentration of branched-chain amino acids was elevated in liver and muscle by exercise in both groups of rats, but the elevated levels in liver were lower in rats fed the FAT diet than in those fed the CHO diet. Serum branched-chain amino acid concentrations were significantly lower in rested rats fed the FAT diet than in those fed the CHO diet, and the leucine and isoleucine concentrations in the former were elevated by exercise, but the serum concentrations in the latter were not significantly affected by exercise. ATP and ADP concentrations in muscle were not significantly affected by either diet or exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了运动对高脂（FAT）或高碳水化合物（CHO）饮食喂养大鼠肝脏和肌肉中支链α-酮酸脱氢酶复合体活性的影响。两个饮食组的大鼠均通过定时喂食法给予等能量饮食，并通过跑步机跑步进行训练。在实验的最后一天，每个饮食组的一半大鼠在处死前进行2小时的跑步运动。在喂食FAT饮食的大鼠肝脏中，运动可使酶复合体的活性状态最大程度升高，但在喂食CHO饮食的大鼠肝脏中则不然，这表明FAT饮食可增强运动期间大鼠肝脏中支链氨基酸的分解代谢。两组大鼠运动后肌肉中酶复合体的活性状态均增强，但两组之间未观察到显著差异。两组大鼠运动后肝脏和肌肉中支链氨基酸的浓度均升高，但喂食FAT饮食的大鼠肝脏中升高的水平低于喂食CHO饮食的大鼠。喂食FAT饮食的静息大鼠血清支链氨基酸浓度显著低于喂食CHO饮食的大鼠，前者的亮氨酸和异亮氨酸浓度因运动而升高，但后者血清浓度未受运动显著影响。肌肉中的ATP和ADP浓度不受饮食或运动的显著影响。（摘要截断于250字）
