title: Effects of AMPK activation on lipolysis in primary rat adipocytes: studies at different glucose concentrations.
abstract: Adipose tissue plays a key role in energy homeostasis. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is an important intracellular energy sensor. Effects of activation of AMPK by aminomidazole-4-carboxamide ribonucleotide (AICAR) on lipolysis in the rat adipocytes were determined in the presence of 3 or 12 mM glucose. Response to epinephrine or dibutyryl-cAMP was higher in the presence of 12 mM glucose. AICAR decreased lipolysis, also when glucose was replaced by alanine or succinate and without decrease in cAMP levels. AICAR attenuated epinephrine-induced decrease in adenosine triphosphate (ATP) levels, reduced glucose uptake and lactate release. These results indicate that short-term activation of AMPK by AICAR in the rat adipocytes inhibits lipolysis, due to changes in the final, followed by protein kinase A (PKA), steps of the lipolytic cascade and improves intracellular energy status. Similar effects of AICAR were observed in the presence of 3 and 12 mM glucose, which indicates that the AMPK system is operative at high glucose concentrations.
authors.affiliation: a Department of Animal Physiology and Biochemistry , Poznan University of Life Sciences , Poznan , Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Szkudelski
authors.affiliation: a Department of Animal Physiology and Biochemistry , Poznan University of Life Sciences , Poznan , Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Szkudelska
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D065567:Absorption, Physiological / Q000187:drug effects; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D000322:Adrenergic Agonists / Q000494:pharmacology; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D004837:Epinephrine / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D006943:Hyperglycemia / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D017208:Rats, Wistar; D012265:Ribonucleotides / Q000494:pharmacology; D015290:Second Messenger Systems / Q000187:drug effects
chemical_list: D000322:Adrenergic Agonists; D007004:Hypoglycemic Agents; D010726:Phosphodiesterase Inhibitors; D012265:Ribonucleotides; D019344:Lactic Acid; D000620:Aminoimidazole Carboxamide; D003994:Bucladesine; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D055372:AMP-Activated Protein Kinases; C031143:AICA ribonucleotide; D005947:Glucose; D004837:Epinephrine
keywords: AMPK; Adipocytes; glucose; lipolysis; metabolism