Horm Metab Res 1993; 25(9): 462-465
DOI: 10.1055/s-2007-1002149
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© Georg Thieme Verlag, Stuttgart · New York

Decreased Glucose Transporter (GLUT 4) Content in Insulin-Sensitive Tissues of Obese Aurothioglucose- and Monosodium Glutamate-Treated Mice

U. F. Machado, Y. Shimizu, M. Saito
  • Department of Biochemistry, Faculty of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
Further Information

Publication History

1992

1993

Publication Date:
14 March 2008 (online)

Summary

We assessed the content of two isoforms of glucose transporter (GLUT 1 and GLUT 4) in insulin-sensitive tissues of hypothalamic obese mice treated with either aurothioglucose (AuTG) or monosodium glutamate (MSG). The animals were studied when obesity had reached a plateau, and they were clearly insulin resistant. We studied different membrane fractions from white adipose tissue (WAT), such as fat-free extract (FFE), plasma membrane (PM) and microsomal (M) fractions. GLUT 4 expressed per protein content displayed a decrease of 50% (p<0.001) in all membrane fractions of AuTG- and MSG-treated mice. The PM GLUT 4 content, expressed per cell surface area, was reduced by 70% (p<0.001) in obese mice, and the total FFE GLUT 4, expressed per total fat mass, was 5 times reduced in obese mice. Compared to control mice, obese mice showed a reduction (p<0.01) of the GLUT 4 amount by 30% (AuTG) and by 40% (MSG) in total membrane fraction (TM) of skeletal and cardiac muscles. Similarly, a reduction of the GLUT 4 amount by 40% (AuTG) and by 45% (MSG) in FFE of brown adipose tissue was observed. The GLUT 1 content in FFE of WAT and TM of skeletal muscle showed no significant difference among the different animal groups. These results confirm a decreased expression of GLUT 4, but not of GLUT 1, in insulin-sensitive tissues, which may contribute to the impaired glucose utilization in these obese animals.

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