Chromium enhances insulin responsiveness via AMPK.pdf.pdf

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Journal of Nutritional Biochemistry 25 (2014) 565–572
Chromium enhances insulin responsiveness via AMPK☆,☆☆
Nolan J. Hoffmana, Brent A. Penquea, Kirk M. Habeggerb,c, Whitney Seallsa,
Lixuan Tacketta, Jeffrey S. Elmendorfa,b,⁎
aDepartment of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
bDepartment of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
cDepartment of Medicine - Endocrinology, Diabetes & Metabolism University of Alabama at Birmingham, Birmingham, AL 35294, USA
Received 28 August 2013; received in revised form 2 January 2014; accepted 24 January 2014
Abstract
Trivalent chromium (Cr3+) is known to improve glucose homeostasis. Cr3+ has been shown to improve plasma membrane-based aspects of glucose
transporter GLUT4 regulation and increase activity of the cellular energy sensor 5’ AMP-activated protein kinase (AMPK). However, the mechanism(s) by which
Cr3+ improves insulin responsiveness and whether AMPK mediates this action is not known. In this study we tested if Cr3+ protected against physiological
hyperinsulinemia-induced plasma membrane cholesterol accumulation, cortical filamentous actin (F-actin) loss and insulin resistance in L6 skeletal muscle
myotubes. In additi