Henderson S A, Black A L, Brooks G A
Am J Physiol. 1985 Aug;249(2 Pt 1):E137-44. doi: 10.1152/ajpendo.1985.249.2.E137.
The effects of training on leucine turnover and oxidation were studied during rest and exercise in young, postabsorptive female rats. Relationships were primarily studied by the continuous infusion method, using [1-14C]leucine. Arterial blood was assayed for leucine specific activity and expired air was monitored for O2 consumption, CO2 production, and the specific activity of 14CO2. The rate of leucine turnover in trained rats was 70% greater than the rate of leucine turnover in untrained rats and was not affected by exercise. By virtue of a higher turnover, the rate of leucine oxidation was 40% greater in trained rats during both rest and exercise. Moreover, leucine oxidation was proportional to the metabolic rate and represented 30% of the leucine turnover at rest and 40-60% of the leucine turnover during exercise. In the same animals leucine turnover was secondarily assessed by measuring the fraction of the [1-14C]leucine dose contained in the hemoglobin pool 4 wk after infusion (occupancy tracer method). Occupancy values for leucine turnover were not different from those determined by the continuous infusion method. The results show that whole body leucine turnover is increased by training and that leucine oxidation is increased by both training and exercise.
研究了训练对年轻的、吸收后状态的雌性大鼠在休息和运动期间亮氨酸周转及氧化的影响。主要采用连续输注法，使用[1-¹⁴C]亮氨酸来研究其中的关系。测定动脉血中亮氨酸的比活性，并监测呼出气体中的耗氧量、二氧化碳产生量以及¹⁴CO₂的比活性。训练大鼠的亮氨酸周转速率比未训练大鼠高70%，且不受运动影响。由于周转速率较高，训练大鼠在休息和运动期间的亮氨酸氧化速率均比未训练大鼠高40%。此外，亮氨酸氧化与代谢率成正比，在休息时占亮氨酸周转的30%，在运动时占亮氨酸周转的40%-60%。在同一批动物中，通过测量输注4周后血红蛋白池中[1-¹⁴C]亮氨酸剂量所占的比例（占据示踪法）对亮氨酸周转进行了二次评估。亮氨酸周转的占据值与连续输注法测定的值没有差异。结果表明，训练可增加全身亮氨酸周转，训练和运动均可增加亮氨酸氧化。
