The metabolic responses of human type I and II muscle fibres during maximal treadmill sprinting.
The metabolic responses of human type I and II muscle fibres during maximal treadmill sprinting.
复制标题
人类 I 型和 II 型肌纤维在跑步机最大冲刺期间的代谢反应。
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
E. Hultman
中科院分区：
文献类型：
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作者：
P. Greenhaff;M. Nevill;K. Soderlund;K. Bodin;L. Boobis;Clyde Williams;E. Hultman
1.取6名健康志愿者S 30次跑台跑前、后股外侧肌活检标本。每个活检样本的一部分用于混合纤维代谢物分析。从每一次活检的剩余部分分离单个纤维，用于ATP、磷酸肌酸(PCR)和糖原测定。2.运动前，II型纤维的PCR值和糖原含量分别为79.3+/-2.7mmol.kgDm-1和47.2mmol.kgDm-1，高于I型纤维(71.3mmol.kgDm)-1和375.25mmol.kgDM-1，P<0.001)。3.峰值功率输出为885+/-66W，运动时下降65+/-3%。运动中II型纤维的磷酸肌酸和糖原降解量(分别为74.3+/-2.5和126.3+/-15.8mmoL(Kg DM)-1)大于I型纤维的相应降解量(分别为5 9.1+/-2.9mmoL(Kg DM)-1，P<0.0 1和77.0±14.3mmoL(Kg DM)-1，P<0.0 1)。当比较纤维类型时，运动过程中ATP的下降是相似的(P>；0.05)。4.与以往类似持续时间的最大骑车运动、等速伸膝和间歇性等长收缩的研究相比，I型纤维记录到的底物利用率极高，接近肢体血流闭塞的剧烈收缩时这种纤维的快速利用率。
1. Muscle biopsy samples were obtained from the vastus lateralis of six healthy volunteers before and after 30 s of treadmill sprinting. A portion of each biopsy sample was used for mixed‐fibre metabolite analysis. Single fibres were dissected from the remaining portion of each biopsy and were used for ATP, phosphocreatine (PCr) and glycogen determination. 2. Before exercise, PCr and glycogen contents were higher in type II fibres (79.3 +/‐ 2.7 and 472 +/‐ 35 mmol (kg dry matter (DM)‐1, respectively) compared with type I fibres (71.3 +/‐ 3.0 mmol (kg DM)‐1, P < 0.01 and 375 +/‐ 25 mmol (kg DM)‐1, P < 0.001, respectively). 3. Peak power output was 885 +/‐ 66 W and declined by 65 +/‐ 3% during exercise. Phosphocreatine and glycogen degradation in type II fibres during exercise (74.3 +/‐ 2.5 and 126.3 +/‐ 15.8 mmol (kg DM)‐1, respectively) was greater than the corresponding degradation in type I fibres (59.1 +/‐ 2.9 mmol (kg DM)‐1, P < 0.001 and 77.0 +/‐ 14.3 mmol (kg DM)‐1, P < 0.01, respectively). The decline in ATP during exercise was similar when comparing fibre types (P > 0.05). 4. Compared with previous studies involving similar durations of maximal cycling exercise, isokinetic knee extension and intermittent isometric contraction, the rates of substrate utilization recorded in type I fibres were extremely high, being close to the rapid rates observed in this fibre type during intense contraction with limb blood flow occluded.