[Effects of beta-adrenoceptor activation on metabolism in neonatal rat cardiomyocytes].
The aim of the present study was to investigate the effects of beta-adrenergic receptor (beta-AR) activation on metabolism in cultured neonatal rat cardiomyocytes. The protein synthesis and total protein content of cardiomyocytes were determined by [(3)H]-leucine incorporation and BCA protein content assay. Cardiomyocyte glucose uptake was measured by [(3)H]-2-deoxy-D-glucose uptake analysis. Adenosine monophosphate activated protein kinase (AMPK) phosphorylation was detected by Western blot. The results showed that sustained stimulation with isoproterenol (ISO), a beta-adrenoceptor agonist, had no effect on [(3)H]-leucine incorporation and total protein content in cardiomyocytes. With beta-AR activation by ISO or NE (pretreated with a selective blocker of the alpha(1)-adrenoceptor prazosin) for 48 h, both the glucose uptake and AMPK phosphorylation increased significantly compared with unstimulated cardiomyocytes. These results suggest that although sustained beta-AR activation has no effect on cardiomyocyte protein metabolism, glucose uptake and AMPK activity are increased significantly. The role of these beta-AR activation-induced changes in cardiac hypertrophy remains to be further investigated.
Yan
Jie
J
Institute of Vascular medicine, peking university third hospital and Key Laboratory of Molecular Cardiology, Education Ministry, Beijing 100083, China.
Chen
Kai
K
Xu
Ming
M
Lu
Zhi-Zhen
ZZ
Han
Qi-De
QD
Zhang
You-Yi
YY
D055372:AMP-Activated Protein Kinases; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D005947:Glucose / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism; D009124:Muscle Proteins / Q000096:biosynthesis*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta
D009097:Multienzyme Complexes; D009124:Muscle Proteins; D011943:Receptors, Adrenergic, beta; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D005947:Glucose