title: Glycolysis preferentially inhibits ATP-sensitive K+ channels in isolated guinea pig cardiac myocytes.
abstract: In heart, glycolysis may be a preferential source of adenosine triphosphate (ATP) for membrane functions. In this study the patch-clamp technique was used to study potassium channels sensitive to intracellular ATP levels in permeabilized ventricular myocytes. Activation of these K+ channels has been implicated in marked cellular K+ loss leading to electrophysiological abnormalities and arrhythmias during myocardial ischemia. The results showed that glycolysis was more effective than oxidative phosphorylation in preventing ATP-sensitive K+ channels from opening. Experiments in excised inside-out patches suggested that key glycolytic enzymes located in the membrane or adjacent cytoskeleton near the channels may account for their preference for glycolytic ATP.
mesh_terms: D000255:Adenosine Triphosphate / Q000502:physiology*; D000818:Animals; D003327:Coronary Disease / Q000503:physiopathology; D006019:Glycolysis; D006168:Guinea Pigs; D006321:Heart / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology*; D009206:Myocardium / Q000166:cytology; D010735:Phosphoglycerate Kinase / Q000502:physiology; D011188:Potassium / Q000502:physiology*; D011770:Pyruvate Kinase / Q000502:physiology
chemical_list: D007473:Ion Channels; D000255:Adenosine Triphosphate; D011770:Pyruvate Kinase; D010735:Phosphoglycerate Kinase; D011188:Potassium