Augmented insulin action on rates of protein synthesis after resistance exercise in rats
Augmented insulin action on rates of protein synthesis after resistance exercise in rats
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DOI：
10.1152/ajpendo.1996.270.2.e313
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发表时间：
1996-02-01
影响因子：
5.1
通讯作者：
Farrell, PA
中科院分区：
文献类型：
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作者：
Fluckey, JD;Vary, TC;Farrell, PA
本研究探讨胰岛素是否对四次抗阻运动后骨骼肌蛋白质合成率有调节作用。雄性大鼠进行阻力运动（急性），要求后肢完全伸展，重量超过肩胛骨，或在没有额外重量的情况下进行站立运动（Nonex）。进行了两项单独的研究。研究1（急性，n = 6; Nonex，n = 6）的蛋白质合成速率通过使用体内泛液剂量方案将[H-3]苯丙氨酸（[H-3]F）掺入肌肉蛋白质中，在运动后16 h进行评估。急性（100 +/- 9 nmol F . g（-1）。h（-1））显著高于Nonex（72 +/- 9 nmol F . g（-1）。h（-1），P < 0.05）。Acute的腓肠肌中的蛋白质合成速率显著高于Nonex（48 ± 7对25 ± 2 nmol F g-1 h-1），但趾长伸肌（EDL）中的蛋白质合成速率不显著。研究2的蛋白质合成率的评估是在抗阻运动后16小时进行的，在原位双侧后肢灌注期间使用[3 H]F掺入肌肉蛋白质，每条腿同时但分开灌注。一条腿的灌注培养基含有胰岛素（6.25 ng/ml），而另一条腿则不含。仅在接受胰岛素的腿部，Acute的比目鱼肌和腓肠肌的蛋白质合成率高于Nonex。对于腓肠肌，急性无胰岛素组的蛋白质合成速率显著低于Nonex有或无胰岛素组。胰岛素对Nonex大鼠任何肌肉的蛋白质合成速率均无影响。运动和胰岛素均不影响EDL的蛋白质合成率。我们的结论是，胰岛素是一个必要的组成部分，在主要由慢或快收缩纤维组成的肌肉的抗阻运动后，蛋白质合成率升高，并需要一个生理扰动（阻力运动在这项研究中），以观察这样的调制，因为蛋白质合成率在Nonex肌肉不受胰岛素的影响。
This study investigated whether insulin has a modulatory effect on protein synthesis rates in skeletal muscle after four sessions of resistance exercise. Male rats engaged in resistance exercise (Acute) that required full extension of the hindlimbs with weights over the scapula or performed the standing movement with no additional weight (Nonex). Two separate studies were conducted. Rates of protein synthesis for study 1 (Acute, n = 6; Nonex, n = 6) were assessed 16 h postexercise by incorporation of [H-3]phenylalanine ([H-3]F) into muscle protein by use of an in vivo flooding dose protocol. Rates of protein synthesis in soleus of Acute (100 +/- 9 nmol F . g(-1). h(-1)) were significantly higher than in Nonex (72 +/- 9 nmol F . g(-1). h(-1), P < 0.05). Rates of protein synthesis were significantly higher in gastrocnemius ofAcute vs. Nonex (48 + 7 vs. 25 + 2 nmol F g-l h-l) but not in extensor digitorum longus (EDL). Assessment ofprotein synthesis rates for study 2 was conducted 16 h after resistance exercise with use of [3H]F incorporation into muscle protein during in situ bilateral hindlimb perfusion, with each leg perfused simultaneously but separately. Perfusion medium for one leg, but not the other, contained insulin (6.25 ng/ml). Soleus and gastrocnemius of Acute had higher protein synthesis rates than Nonex only in the leg that received insulin. For gastrocnemius, rates of protein synthesis in Acute without insulin were significantly lower than in Nonex with or without insulin. Insulin had no effect on protein synthesis rates for any muscle in Nonex rats. Neither exercise nor insulin affected protein synthesis rates in EDL. We conclude that insulin is a necessary component in elevated protein synthesis rates after resistance exercise in muscles composed of primarily slow- or fast-twitch fibers, and that a physiological perturbation (resistance exercise in this study) is required to observe such modulation, because rates of protein synthesis in Nonex muscles were not influenced by insulin.