Effect of tension on contraction-induced glucose transport in rat skeletal muscle
Effect of tension on contraction-induced glucose transport in rat skeletal muscle
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DOI：
10.1152/ajpendo.1999.277.2.e208
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发表时间：
1999-08-01
影响因子：
5.1
通讯作者：
Galbo, H
中科院分区：
文献类型：
--
作者：
Ihlemann, J;Ploug, T;Galbo, H
我们质疑收缩诱导的肌肉葡萄糖转运仅取决于刺激频率而不是工作负荷的普遍观点。孵育比目鱼肌肌肉电刺激在一个给定的模式为5分钟。休息长度进行调整，以实现无力（0%P），最大的力量（100%P），或50%的最大力量（50%P）。葡萄糖转运（2-脱氧-D-葡萄糖摄取）直接随力的发展而增加（P < 0.05）[27 +/- 2（基础），45 +/- 2（0% P），68 +/- 3（50% P）和94 +/- 3（100% P）nmol.g（-1. 5 min（-1）]。糖原在0%P时下降，但不随力的发展而进一步变化（P > 0.05）。与不用力时相比，用力时乳酸、AMP和IMP浓度升高（P < 0.05），ATP浓度降低（P < 0.05）。5 '-AMP活化蛋白激酶（AMPK）活性随力直接增加[20 +/- 2（基础）、60 +/- 11（0% P）、91 +/- 12（50% P）和109 +/- 12（100% P）pmol.mg（-1）.min（-1）]。被动牵张（类似于86%P）使葡萄糖转运加倍，而不改变代谢。总之，收缩诱导的肌肉葡萄糖转运直接随力的发展而变化，并且不仅仅由刺激频率决定。AMPK活性可能是收缩诱导的葡萄糖转运的重要决定因素。相反，糖原浓度本身并不起主要作用。最后，被动拉伸本身增加了肌肉中的葡萄糖转运。
We questioned the general view that contraction-induced muscle glucose transport only depends on stimulation frequency and not on workload. Incubated soleus muscles were electrically stimulated at a given pattern for 5 min. Resting length was adjusted to achieve either no force (0% P), maximum force (100% P), or 50% of maximum force (50% P). Glucose transport (2-deoxy-D-glucose uptake) increased directly with force development (P < 0.05) [27 +/- 2 (basal), 45 +/- 2 (0% P), 68 +/- 3 (50% P), and 94 +/- 3 (100% P) nmol.g(-1).5 min(-1)]. Glycogen decreased at 0% P but did not change further with force development (P > 0.05). Lactate, AMP, and IMP concentrations were higher (P < 0.05) and ATP concentrations lower (P < 0.05) when force was produced than when it was not. 5'-AMP-activated protein kinase (AMPK) activity increased directly with force [20 +/- 2 (basal), 60 +/- 11 (0% P), 91 +/- 12 (50% P), and 109 +/- 12 (100% P) pmol.mg(-1).min(-1)]. Passive stretch (similar to 86% P) doubled glucose transport without altering metabolism. In conclusion, contraction-induced muscle glucose transport varies directly with force development and is not solely determined by stimulation frequency. AMPK activity is probably an essential determinant of contraction-induced glucose transport. In contrast, glycogen concentrations per se do not play a major role. Finally, passive stretch per se increases glucose transport in muscle.