Chemical hypoxia-induced glucose transporter-4 translocation in neonatal rat cardiomyocytes.
BACKGROUND
AMP-activated protein kinase (AMPK) activation plays an essential role in glucose metabolism of the heart. This study aimed at investigating whether AMPK was involved in glucose transporter-4 (GLUT-4) translocation induced by azide-induced chemical hypoxia in primary cultured neonatal rat cardiomyocytes.


METHODS
With or without adenine 9-beta-D-arabinofuranoside (ara A, AMPK inhibitor) preincubation, primary cultured rat cardiomyocytes were randomized to several groups as incubated with azide (the respiratory chain inhibitor), insulin, or 5-aminoimidazole-4-carboxyamide-1-beta-D-ribofuranoside (AICAR, an AMPK activator). Glucose uptake was measured through gamma-scintillation and GLUT-4 protein was detected by Western blot for each group.


RESULTS
Azide-induced chemical hypoxia and AICAR both increased glucose uptake and GLUT-4 translocation in cardiomyocytes, and AICAR had an additive effect on insulin action. Ara A decreased AICAR- and azide-induced glucose uptake and GLUT-4 translocation but did not affect basal or insulin-stimulated glucose uptake.


CONCLUSIONS
Azide-induced chemical hypoxia increased glucose uptake and GLUT-4 translocation in neonatal rat cardiomyocytes through a mechanism that at least was partially mediated by AMPK activation.
Guan
Fu
F
Department of Cardiology, The First Affiliated Hospital, China Medical University, Shenyang, China.
Yu
Bo
B
Qi
Guo-xian
GX
Hu
Jian
J
Zeng
Ding-yin
DY
Luo
Jia
J
D000091162:AMP-Activated Protein Kinase Kinases; D055372:AMP-Activated Protein Kinases; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D015687:Cell Hypoxia; D051275:Glucose Transporter Type 4 / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012265:Ribonucleotides / Q000494:pharmacology; D019810:Sodium Azide / Q000633:toxicity
D051275:Glucose Transporter Type 4; D007004:Hypoglycemic Agents; D009097:Multienzyme Complexes; D047428:Protein Kinase Inhibitors; D012265:Ribonucleotides; D000620:Aminoimidazole Carboxamide; D019810:Sodium Azide; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D000091162:AMP-Activated Protein Kinase Kinases; D055372:AMP-Activated Protein Kinases; C031143:AICA ribonucleotide