Rac1 governs exercise-stimulated glucose uptake in skeletal muscle through regulation of GLUT4 translocation in mice

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Exercise increase skeletal muscle energy turnover and one of the important substrates for the working muscle is glucose taken up from the blood. Despite extensive efforts, the signaling mechanisms vital for glucose uptake during exercise are not yet fully understood but the GTPase Rac1 is a candidate molecule. This study investigated the role of Rac1 in muscle glucose uptake and substrate utilization during treadmill exercise in mice in vivo. Exercise-induced uptake of radiolabelled 2-deoxyglucose (2-DG) at 65% max running capacity was blocked in soleus and decreased by 80 and 60% in gastrocnemius and tibialis anterior muscles, respectively, in muscle-specific inducible Rac1 knockout (mKO) mice compared to wildtype littermates. By developing an assay to quantify endogenous GLUT4 translocation, we observed that GLUT4 content at the sarcolemma in response to exercise was reduced in Rac1 mKO muscle. Our findings implicate Rac1 as a regulatory element critical for controlling glucose uptake during exercise via regulation of GLUT4 translocation. This article is protected by copyright. All rights reserved.

Original languageEnglish
JournalJournal of Physiology
Issue number17
Pages (from-to)4997-5008
Number of pages12
Publication statusPublished - 2016

ID: 161001827