Graham T E, Adamo K B, Shearer J, Marchand I, Saltin B
Human Biology and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
J Appl Physiol (1985). 2001 Mar;90(3):873-9. doi: 10.1152/jappl.2001.90.3.873.
We examined the net catabolism of two pools of glycogen, proglycogen (PG) and macroglycogen (MG), in human skeletal muscle during exercise. Male subjects (n = 21) were assigned to one of three groups. Group 1 exercised 45 min at 70% maximal O(2) uptake (VO(2 max)) and had muscle biopsies at rest, 15 min, and 45 min. Group 2 exercised at 85% VO(2 max) to exhaustion (45.4 +/- 3.4 min) and had biopsies at rest, 10 min, and exhaustion. Group 3 performed three 3-min bouts of exercise at 100% VO(2 max) separated by 6 min of rest. Biopsies were taken at rest and after each bout. Group 1 had small MG and PG net glycogenolysis rates (ranging from 3.8 +/- 1.0 to 2.4 +/- 0.6 mmol glucosyl units. kg(-1). min(-1)) that did not change over time. In group 2, the MG glycogenolysis rate remained low and unchanged over time, whereas the PG rate was initially elevated (11.3 +/- 2.3 mmol glucosyl units. kg(-1). min(-1)) and declined (P < or = 0.05) with time. During the first 10 min, PG concentration ([PG]) declined (P < or = 0.05), whereas MG concentration ([MG]) did not. Similarly, in group 3, in both the first and the second bouts of exercise [PG] declined (P < or = 0.05) and [MG] did not, although by the end of the second exercise period the [MG] was lower (P < or = 0.05) than the rest level. The net catabolic rates for PG in the first two exercises were 22.6 +/- 6.8 and 21.8 +/- 8.2 mmol glucosyl units. kg(-1). min(-1), whereas the corresponding values for MG were 17.6 +/- 6.0 and 10.8 +/- 5.6. The MG pool appeared to be more resistant to mobilization, and, when activated, its catabolism was inhibited more rapidly than that of PG. This suggests that the metabolic regulation of the two pools must be different.
我们研究了运动期间人体骨骼肌中两个糖原池，即前糖原（PG）和大糖原（MG）的净分解代谢情况。男性受试者（n = 21）被分为三组。第一组以最大摄氧量（VO₂max）的70%进行45分钟运动，并在静息、运动15分钟和45分钟时进行肌肉活检。第二组以85% VO₂max运动至力竭（45.4±3.4分钟），并在静息、运动10分钟和力竭时进行活检。第三组以100% VO₂max进行三次3分钟的运动，每次运动间隔6分钟休息。在静息时以及每次运动后进行活检。第一组的MG和PG净糖原分解率较低（范围为3.8±1.0至2.4±0.6毫摩尔葡萄糖基单位·千克⁻¹·分钟⁻¹），且随时间没有变化。在第二组中，MG糖原分解率随时间保持较低且不变，而PG率最初升高（11.3±2.3毫摩尔葡萄糖基单位·千克⁻¹·分钟⁻¹），并随时间下降（P≤0.05）。在最初的10分钟内，PG浓度（[PG]）下降（P≤0.05），而MG浓度（[MG]）没有下降。同样，在第三组中，在第一次和第二次运动期间[PG]均下降（P≤0.05），[MG]没有下降，尽管在第二次运动结束时[MG]低于静息水平（P≤0.05）。前两次运动中PG的净分解率分别为22.6±6.8和21.8±8.2毫摩尔葡萄糖基单位·千克⁻¹·分钟⁻¹，而MG的相应值分别为17.6±6.0和10.8±5.6。MG池似乎对动员更具抗性，并且在被激活时，其分解代谢比PG的分解代谢更快受到抑制。这表明两个糖原池的代谢调节必定不同。
