Decrease in myostatin by ladder-climbing training is associated with insulin resistance in diet-induced obese rats

作者：Liang Tang, Kai Luo, Chentao Liu, Xudan Wang, Didi Zhang, Aiping Chi, Jing Zhang, Lijun Sun · 发表于：Chinese Medical Journal · 年份：2014 · DOI：10.3760/cma.j.issn.0366-6999.20140022 · 被引用次数：22 · 研究领域：Muscle Physiology and Disorders、Adipose Tissue and Metabolism、Cardiovascular and exercise physiology

BACKGROUND: Suppression of myostatin (MSTN) has been associated with skeletal muscle atrophy and insulin resistance (IR). However, few studies link MSTN suppression by ladder-climbing training (LCT) and IR. Therefore, we intended to identify the correlation with IR between LCT and to analyze the signaling pathways through which MSTN suppression by LCT regulates IR. METHODS: The rats were randomly assigned to two types of diet: normal pellet diet (NPD, n = 8) and high-fat diet (HFD, n = 16). After 8 weeks, the HFD rats were randomly re-assigned to two groups (n = 8 for each group): HFD sedentary (HFD-S) and high-fat diet ladder-climbing training (HFD-LCT). HFD-LCT rats were assigned to LCT for 8 weeks. Western blotting, immunohistochemistry and enzyme assays were used to measure expression levels and activities of MSTN, GLUT4, PI3K, Akt and Akt-activated targets (mTOR, FoxO1 and GSK-3β). RESULTS: The LCT significantly improved IR and whole-body insulin sensitivity in HDF-fed rats. MSTN protein levels decreased in matching serum (42%, P = 0.007) and muscle samples (25%, P = 0.035) and its receptor mRNA expression also decreased (16%, P = 0.041) from obese rats after LCT. But the mRNA expression of insulin receptor had no obvious changes in LCT group compared with NPD and HFD-S groups (P = 0.074). The ladder-climbing training significantly enhanced PI3K activity (1.7-fold, P = 0.024) and Akt phosphorylation (83.3%, P = 0.022) in HFD-fed rats, significantly increased GLUT4 protei...