Thomson J A, Green H J, Houston M E
Pflugers Arch. 1979 Feb 14;379(1):105-8. doi: 10.1007/BF00622912.
Muscle glycogen depletion in ST, FTa and FTb fibres were studied in human subjects undergoing two distinctly different modes of bicycle exercise. Two hours of submaximal exercise (60% of VO2 max) produced a 77% decline in muscle glycogen concentration accompanied by only minor elevations in muscle and blood lactate levels whereas 10 one minute supramaximal work bouts resulted in a 52% decrease in total glycogen concentration and substantially elevated muscle and blood lactate contents. Moreover the patterns of glycogen depletion in the two conditions were also distinctly different. Based on the PAS staining intensity, glycogen was depleted the most in ST fibres and least in FTb fibres, during submaximal work. During supramaximal work FTb fibres were the lightest in PAS staining, with little loss of glycogen from ST fibres. In both situations the loss of glycogen in the FTa fibres was intermediate compared to the other two fibre types. These data support a selective recruitment of muscle fibres during work of different intensities, and further, suggest a physiological basis for the subgrouping of FT fibres in man.
在进行两种截然不同的自行车运动模式的人类受试者中，研究了慢肌纤维（ST）、快肌纤维a型（FTa）和快肌纤维b型（FTb）中的肌肉糖原消耗情况。两小时的次最大强度运动（最大摄氧量的60%）使肌肉糖原浓度下降了77%，同时肌肉和血液中的乳酸水平仅略有升高；而10次持续一分钟的超最大强度运动则导致总糖原浓度下降了52%，肌肉和血液中的乳酸含量大幅升高。此外，两种情况下糖原消耗的模式也明显不同。根据过碘酸希夫（PAS）染色强度，在次最大强度运动期间，ST纤维中的糖原消耗最多，FTb纤维中的糖原消耗最少。在超最大强度运动期间，FTb纤维的PAS染色最浅，ST纤维的糖原损失很少。在两种情况下，FTa纤维中的糖原损失与其他两种纤维类型相比处于中间水平。这些数据支持了在不同强度运动期间肌肉纤维的选择性募集，并且进一步表明了人类FT纤维亚分组的生理基础。
