Post-ischemic stimulation of 2-deoxyglucose uptake in rat myocardium: role of translocation of Glut-4

J Mol Cell Cardiol. 1998 Feb;30(2):393-403. doi: 10.1006/jmcc.1997.0602.

Abstract

Myocardial ischemia elicits translocation of the insulin-sensitive glucose transporter GLUT-4 from intracellular membrane stores to the sarcolemma. Because glucose metabolism is of crucial importance for post-ischemic recovery of the heart, myocardial uptake of [3H]-labeled 2-deoxyglucose and subcellular localization of GLUT-4 were determined during reperfusion in isolated rat hearts perfused with medium containing 0.4 mm palmitate and 8 mm glucose. Hearts were subjected to 20 min of no-flow ischemia, followed by reperfusion for up to 60 min. Subcellular localization of GLUT-4 was determined by cell fractionation followed by immunoblotting. After 15 and 60 min of reperfusion uptake of 2-deoxyglucose was significantly higher (91+/-9 and 96+/-8 nmol/min/g wet weight, respectively) as compared to control values (65+/-1 nmol/min/g wet weight). Ischemia elicited translocation of GLUT-4 to the sarcolemma, which persisted after 15 min of reperfusion. However, after 60 min of reperfusion the subcellular distribution of GLUT-4 was similar to control hearts. In conclusion, reversal of ischemia-induced translocation of GLUT-4 to the sarcolemma is rather slow, possibly facilitating glucose uptake early during reperfusion. However, myocardial uptake and phosphorylation of 2-deoxyglucose remains enhanced late during reperfusion, when pre-ischemic distribution of GLUT-4 is almost completely restored, indicating that additional mechanisms are likely to be involved in post-ischemic stimulation of glucose uptake.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport, Active / drug effects
  • Deoxyglucose / metabolism*
  • Glucose / metabolism
  • Glucose Transporter Type 1
  • Glucose Transporter Type 4
  • Glycolysis
  • In Vitro Techniques
  • Insulin / pharmacology
  • Kinetics
  • Male
  • Monosaccharide Transport Proteins / genetics*
  • Monosaccharide Transport Proteins / metabolism
  • Muscle Proteins*
  • Myocardial Reperfusion Injury / metabolism*
  • Myocardial Reperfusion Injury / physiopathology
  • Myocardium / metabolism*
  • Perfusion
  • Rats
  • Sarcolemma / metabolism
  • Subcellular Fractions / metabolism
  • Ventricular Function, Left

Substances

  • Glucose Transporter Type 1
  • Glucose Transporter Type 4
  • Insulin
  • Monosaccharide Transport Proteins
  • Muscle Proteins
  • Slc2a4 protein, rat
  • Deoxyglucose
  • Glucose