title: Acute regulation of 5'-AMP-activated protein kinase by long-chain fatty acid, glucose and insulin in rat primary adipocytes.
abstract: Palmitate increased AMPK (5'-AMP-activated protein kinase) activity, glucose utilization and 2-DOG (2-deoxyglucose) transport in rat adipocytes. All three effects were blocked by the AMPK inhibitor Compound C, leading to the conclusion that in response to an increase in long-chain NEFA (non-esterified fatty acid) concentration AMPK mediated an enhancement of adipocyte glucose transport, thereby providing increased glycerol 3-phosphate for FA (fatty acid) esterification to TAG (triacylglycerol). Activation of AMPK in response to palmitate was not due to an increase in the adipocyte AMP:ATP ratio. Glucose decreased AMPK activity and effects of palmitate and glucose on AMPK activity were antagonistic. While insulin had no effect on basal AMPK activity insulin did decrease AMPK activity in the presence of palmitate and also decreased the percentage effectiveness of palmitate to increase the transport of 2-DOG. It is suggested that activation of adipocyte AMPK by NEFA, as well as decreasing the activity of hormone-sensitive lipase, could modulate adipose tissue dynamics by increasing FA esterification and, under certain circumstances, FA synthesis.
authors.affiliation: Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Abdel
authors.initials: A
authors.lastname: Hebbachi
authors.forename: David
authors.initials: D
authors.lastname: Saggerson
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D017667:Adipocytes / Q000187:drug effects / Q000201:enzymology*; D000494:Allosteric Regulation; D000818:Animals; D001692:Biological Transport; D002478:Cells, Cultured; D003847:Deoxyglucose / Q000494:pharmacology*; D004789:Enzyme Activation; D057075:Enzyme Assays; D004951:Esterification; D005947:Glucose / Q000378:metabolism; D061385:Insulins / Q000494:pharmacology*; D008297:Male; D019308:Palmitic Acid / Q000494:pharmacology*; D061251:Primary Cell Culture; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D061385:Insulins; D019308:Palmitic Acid; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D003847:Deoxyglucose; D055372:AMP-Activated Protein Kinases; C568305:Prkaa1 protein, rat; D005947:Glucose