Insulin-nonspecific reduction in skeletal muscle glucose transport in high-fat-fed rats

Metabolism. 2004 Jul;53(7):912-7. doi: 10.1016/j.metabol.2003.12.026.

Abstract

High-fat feeding diminishes insulin-stimulated glucose transport in skeletal muscle. However, conflicting results are reported regarding whether phosphatidylinositol (PI)-3 kinase-independent glucose transport is also impaired in insulin-resistant high-fat-fed rodents. The aim of the present study was to study whether non-insulin-dependent mechanisms for stimulation of glucose transport are defective in skeletal muscle from high-fat-fed rats. Rats were fed normal chow diet or high-fat diet for 4 weeks and isolated epitrochlearis muscles were used for measuring glucose transport. Insulin-stimulated glucose transport was significantly lower in rats fed the high-fat diet compared with chow-fed rats (P < .05). Hypoxia-stimulated glucose transport was also reduced in high-fat-fed rats (P < .05). Nevertheless, hypoxia-stimulated adenosine monophosphate-activated protein kinase (AMPK) phosphorylation (Thr172) level was not affected by high-fat feeding. Glucose transport by sodium nitroprusside stimulation was reduced in high-fat-fed rats (P < .05). Protein content of glucose transporter (GLUT)-4 and AMPK-alpha, and glycogen content were comparable between both groups. Our findings provide evidence that high-fat feeding can affect not only insulin but also non-insulin-stimulated glucose transport. A putative defect in common steps in glucose transport may play a role to account for impaired insulin-stimulated glucose transport in rats fed a high-fat diet.

MeSH terms

  • Adenylate Kinase / metabolism
  • Aminoimidazole Carboxamide / analogs & derivatives*
  • Aminoimidazole Carboxamide / pharmacology
  • Animals
  • Biological Transport, Active / drug effects
  • Blotting, Western
  • Dietary Fats / pharmacology*
  • Glucose / metabolism*
  • Glucose Transporter Type 4
  • Hypoglycemic Agents / pharmacology*
  • In Vitro Techniques
  • Insulin / pharmacology*
  • Male
  • Monosaccharide Transport Proteins / metabolism
  • Muscle Proteins*
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / enzymology
  • Muscle, Skeletal / metabolism*
  • Nitric Oxide Donors / pharmacology
  • Nitroprusside / pharmacology
  • Phosphatidylinositol 3-Kinases / metabolism
  • Rats
  • Rats, Wistar
  • Ribonucleotides / pharmacology

Substances

  • Dietary Fats
  • Glucose Transporter Type 4
  • Hypoglycemic Agents
  • Insulin
  • Monosaccharide Transport Proteins
  • Muscle Proteins
  • Nitric Oxide Donors
  • Ribonucleotides
  • Slc2a4 protein, rat
  • Nitroprusside
  • Aminoimidazole Carboxamide
  • Phosphatidylinositol 3-Kinases
  • Adenylate Kinase
  • AICA ribonucleotide
  • Glucose