Czarkowska-Paczek B, Zendzian-Piotrowska M, Gala K, Sobol M, Paczek L
Department of Biophysics and Human Physiology, Medical University of Warsaw, Warsaw, Poland.
J Physiol Pharmacol. 2014 Jun;65(3):449-54.
Irisin induces the browning of adipose tissue. The goal of this study was to investigate the influence of acute exercise in untrained and trained rats and endurance training on FNDC5 mRNA and irisin levels in white and red skeletal muscle and serum. Rats (n=60) were randomly divided into two groups: untrained and trained (subjected to 6-week endurance training with increasing load). Subgroups of rats from each group were sacrificed before (controls), immediately after, or 3 hours following acute exercise with the same work load. Muscle samples (red and white) and serum were collected. FNDC5 mRNA was evaluated using RT-PCR. Irisin levels were measured using an immunoenzymatic method. Muscle FNDC5 mRNA decreased immediately after acute exercise compared with baseline levels, but not in red muscle in trained rats. Atrend toward a return to baseline appeared 3 hours after the exercise, but only in white muscle in untrained group. Irisin protein levels increased after acute exercise in red muscle 3 hours post-exercise compared with samples taken immediately after exercise, and decreased 3 hours post-exercise compared to pre-exercise level in white muscles. FNDC5 mRNA did not change following training, whereas irisin protein levels increased in red muscle and decreased in white muscle. Serum irisin levels remained unchanged following acute exercise and training. We concluded that changes in irisin mRNA and protein levels in rat muscle after acute exercise are limited and depend on training status and the muscle type. Irisin serum levels remained stable after acute exercise or endurance training.
鸢尾素可诱导脂肪组织褐变。本研究的目的是调查急性运动对未训练和已训练大鼠的影响，以及耐力训练对白色和红色骨骼肌及血清中FNDC5 mRNA和鸢尾素水平的影响。大鼠（n = 60）被随机分为两组：未训练组和已训练组（进行为期6周的负荷递增耐力训练）。每组大鼠的亚组在急性运动前（对照组）、运动后即刻或运动后3小时处死，急性运动的工作量相同。收集肌肉样本（红色和白色）及血清。使用RT-PCR评估FNDC5 mRNA。使用免疫酶法测量鸢尾素水平。与基线水平相比，急性运动后即刻肌肉FNDC5 mRNA下降，但已训练大鼠的红色肌肉中未下降。运动后3小时出现恢复至基线水平的趋势，但仅在未训练组的白色肌肉中出现。与运动后即刻采集的样本相比，运动后3小时红色肌肉中鸢尾素蛋白水平在急性运动后升高，与运动前水平相比，白色肌肉中运动后3小时鸢尾素蛋白水平下降。训练后FNDC5 mRNA未发生变化，而红色肌肉中鸢尾素蛋白水平升高，白色肌肉中鸢尾素蛋白水平下降。急性运动和训练后血清鸢尾素水平保持不变。我们得出结论，急性运动后大鼠肌肉中鸢尾素mRNA和蛋白水平的变化有限，且取决于训练状态和肌肉类型。急性运动或耐力训练后血清鸢尾素水平保持稳定。
