Increased GLUT-4 translocation mediates enhanced insulin sensitivity of muscle glucose transport after exercise

J Appl Physiol (1985). 1998 Oct;85(4):1218-22. doi: 10.1152/jappl.1998.85.4.1218.

Abstract

The purpose of this study was to determine whether the increase in insulin sensitivity of skeletal muscle glucose transport induced by a single bout of exercise is mediated by enhanced translocation of the GLUT-4 glucose transporter to the cell surface. The rate of 3-O-[3H]methyl-D-glucose transport stimulated by a submaximally effective concentration of insulin (30 microU/ml) was approximately twofold greater in the muscles studied 3.5 h after exercise than in those of the sedentary controls (0.89 +/- 0.10 vs. 0.43 +/- 0.05 micromol . ml-1 . 10 min-1; means +/- SE for n = 6/group). GLUT-4 translocation was assessed by using the ATB-[2-3H]BMPA exofacial photolabeling technique. Prior exercise resulted in greater cell surface GLUT-4 labeling in response to submaximal insulin treatment (5.36 +/- 0.45 dpm x 10(3)/g in exercised vs. 3.00 +/- 0.38 dpm x 10(3)/g in sedentary group; n = 10/group) that closely mirrored the increase in glucose transport activity. The signal generated by the insulin receptor, as reflected in the extent of insulin receptor substrate-1 tyrosine phosphorylation, was unchanged after the exercise. We conclude that the increase in muscle insulin sensitivity of glucose transport after exercise is due to translocation of more GLUT-4 to the cell surface and that this effect is not due to potentiation of insulin-stimulated tyrosine phosphorylation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 3-O-Methylglucose / pharmacokinetics*
  • Affinity Labels
  • Animals
  • Azides / pharmacokinetics
  • Biological Transport
  • Cell Membrane / metabolism
  • Disaccharides / pharmacokinetics
  • Glucose Transporter Type 4
  • Glycosides
  • Insulin / pharmacology
  • Insulin / physiology*
  • Male
  • Monosaccharide Transport Proteins / metabolism*
  • Muscle Proteins*
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / physiology*
  • Physical Exertion / physiology*
  • Propylamines*
  • Rats
  • Rats, Wistar
  • Swimming
  • Tritium

Substances

  • Affinity Labels
  • Azides
  • Disaccharides
  • Glucose Transporter Type 4
  • Glycosides
  • Insulin
  • Monosaccharide Transport Proteins
  • Muscle Proteins
  • Propylamines
  • Slc2a4 protein, rat
  • Tritium
  • 2-N-(4-(1-azitrifluoroethyl)benzoyl)-1,3-bis-(mannos-4-yloxy)-2-propylamine
  • 3-O-Methylglucose