Effects of polarizing solution on glucose uptake of rat oxygenated or hypoxic ventricular myocytes.
1. Although adult cardiac metabolism depends on fatty acids rather than on carbohydrates, hypoxic hearts consume glucose and infusion with a glucose-insulin-potassium solution (GIK) helps in the recovery of the pressure register, the heart rate and electrocardiogram of rat hypoxic whole hearts. 2. Rat myocytes obtained by enzymatic disaggregation captured significant amounts of glucose in Tyrode's solution (9.8 +/- 2.05% during oxygenation and 16.26 +/- 2.76% during hypoxia) after 60 min incubation. Cells incubated with GIK showed a significantly increased glucose uptake (to 30.04 +/- 1.99% during oxygenation and to 37.06 +/- 1.97% during hypoxia). 3. Glucose was the component of the Tyrode's solution that most enhanced its own entry, increasing glucose entry to 45.42 +/- 2.64% with oxygen and 41.42 +/- 2.69% under hypoxia. 4. Antibodies against glucose transporters 1 and 4 (GLUT-1 and -4, respectively) decreased glucose transport during GIK treatment under hypoxia. 5. We conclude that GIK has beneficial effects mediated by GLUT-1 and -4 during hypoxia, inducing recovery of the damaged tissue.
Carbó
Roxana
R
Multidisciplinary Program of Molecular Biomedicine CINVESTAV-IPN and Physiology Department, Instituto Nacional de Cardiología 'Ignacio Chávez', Mexico City, Mexico. roxcarboz@yahoo.com
Nava
Pilar
P
Guarner
Verónica
V
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000860:Hypoxia / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D007552:Isotonic Solutions / Q000494:pharmacology*; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D000906:Antibodies; D007328:Insulin; D007552:Isotonic Solutions; D009004:Monosaccharide Transport Proteins; C037692:Tyrode's solution; D005947:Glucose; D011188:Potassium; D010100:Oxygen