Differential effects of GLUT-1 or GLUT-4 overexpression on insulin responsiveness in transgenic mice.

Abstract

The effect of glucose transporter expression on insulin-stimulated whole body glucose disposal was examined in transgenic mice overexpressing GLUT-1 or GLUT-4. Transgenic mice and their control littermates were subjected to a euglycemic hyperinsulinemic clamp under pentobarbital sodium anesthesia using an insulin infusion rate of 20 mU.kg-1.min-1 and a variable glucose infusion rate (GIR). Fasted mice overexpressing GLUT-1 in skeletal muscle exhibited a GIR that was only 54% that of controls (19.3 +/- 1.8 vs. 36.0 +/- 3.9 mg.kg-1.min-1) when blood glucose was clamped at euglycemic values. In contrast, fasted mice overexpressing GLUT-4 in fat and muscle exhibited a GIR that was 40% higher than controls (53.9 +/- 2.3 vs. 39.1 +/- 2.5 mg.kg-1.min-1). At the end of the clamp, beta-hydroxybutyrate levels were 10-fold higher in the GLUT-1 transgenic mice relative to nontransgenic littermates (2.0 +/- 0.6 vs. 0.2 +/- 0.1 mM) but did not differ between the GLUT-4 transgenic mice and their control littermates (0.3 +/- 0.1 vs. 0.3 +/- 0.1 mM). These data demonstrate that the level of expression of a glucose transporter in muscle and fat can have marked effects on whole body glucose homeostasis and fuel metabolism. Insulin responsiveness was enhanced by overexpression of GLUT-4. Strikingly, however, overexpression of GLUT-1 in muscle induced a profound reduction in insulin-stimulated whole body glucose disposal.(ABSTRACT TRUNCATED AT 250 WORDS)

Statistics

0200400'97'99'01'03'05'07'09'11'13'15'17
Citations per Year

951 Citations

Semantic Scholar estimates that this publication has 951 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Marshall1994DifferentialEO, title={Differential effects of GLUT-1 or GLUT-4 overexpression on insulin responsiveness in transgenic mice.}, author={Bess A. Marshall and Mike M Mueckler}, journal={The American journal of physiology}, year={1994}, volume={267 5 Pt 1}, pages={E738-44} }