Endothelial Na+-D-glucose cotransporter: no role in insulin-mediated glucose uptake

Horm Metab Res. 2005 Nov;37(11):657-61. doi: 10.1055/s-2005-870574.

Abstract

A recent report indicates that the Na+-D-glucose cotransporter SGLT1 is present in capillaries of skeletal muscle and is required for insulin-mediated glucose uptake in myocytes. This result is based on the complete inhibition of insulin-mediated muscle glucose uptake by phlorizin, an inhibitor of SGLT1. Using the pump-perfused rat hind limb, we measured glucose uptake, lactate efflux, and radioactive 2-deoxyglucose uptake into individual muscles with saline (control), phlorizin, insulin, and insulin plus phlorizin, as well as with saline and insulin using normal and low Na+ perfusion buffer. Insulin-mediated glucose uptake was not inhibited after correction for phlorizin interference in the glucose assay. Lactate efflux and 2-deoxyglucose uptake by individual muscles were unaffected by phlorizin. Low Na+ buffer did not affect insulin-mediated glucose uptake, lactate efflux, or 2-deoxyglucose uptake. We conclude that endothelial SGLT1 exerts no barrier for glucose delivery to myocytes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Endothelium, Vascular / physiology*
  • Glucose / metabolism*
  • Hindlimb / metabolism
  • Insulin / pharmacology*
  • Male
  • Phlorhizin / pharmacology
  • Rats
  • Rats, Wistar
  • Sodium-Glucose Transporter 1 / physiology*

Substances

  • Insulin
  • Slc5a1 protein, rat
  • Sodium-Glucose Transporter 1
  • Phlorhizin
  • Glucose