Effect of transient ischemia on the expression of glucose transporters GLUT-1 and GLUT-4 in rat myocardium.
A number of observations indicate that myocardial glucose utilization is increased late during post-ischemic reperfusion. The present study was designed to examine whether transient ischemia elicits altered expression of glucose transporters GLUT-1 and GLUT-4. In rats, the left anterior descending coronary artery was occluded for 20 min followed by reperfusion for 1, 3 or 7 days. Regional myocardial uptake and phosphorylation of glucose was determined based on myocardial accumulation of 2-deoxy-D-[2, 6-3H]glucose-6-phosphate. In hearts from fasted rats, after 3 days of reperfusion, myocardial uptake and phosphorylation of glucose was 48% higher in the reperfused region compared to a remote control region. No regional difference in myocardial glucose uptake and phosphorylation was detectable in hearts from fed rats. After 1 day of reperfusion, expression of myocardial glucose transporter GLUT-1 mRNA was increased to 195+/-24% (mean+/-SEM) of the value measured in the remote region and the expression of GLUT-4 mRNA was decreased to 58+/-7%. After 3 days of reperfusion both mRNA and protein of GLUT-1 were higher in the reperfused region, averaging 133+/-23% and 249+/-36%, respectively. The corresponding values for GLUT-4 mRNA and protein were 77+/-7% and 62+/-6%, respectively. The results indicate that a short period of ischemia alters the expression of glucose transporter isoforms GLUT-1 and GLUT-4. Observed changes may be involved in the mechanisms underlying late changes of substrate metabolism during reperfusion.
Tardy-Cantalupi
I
I
Department of Internal Medicine, University Hospital, Geneva, Switzerland.
Montessuit
C
C
Papageorgiou
I
I
Remondino-Müller
A
A
Assimacopoulos-Jeannet
F
F
Morel
D R
DR
Lerch
R
R
D000208:Acute Disease; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D003847:Deoxyglucose / Q000378:metabolism; D005227:Fatty Acids / Q000097:blood; D005815:Genetic Code; D051272:Glucose Transporter Type 1; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000097:blood; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009124:Muscle Proteins; D017202:Myocardial Ischemia / Q000378:metabolism*; D015425:Myocardial Reperfusion; D010766:Phosphorylation; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D005227:Fatty Acids; D051272:Glucose Transporter Type 1; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D012333:RNA, Messenger; C495679:Slc2a1 protein, rat; C495694:Slc2a4 protein, rat; D009320:Atrial Natriuretic Factor; D003847:Deoxyglucose