title: Upstream signaling of protein kinase C-epsilon in xenon-induced pharmacological preconditioning. Implication of mitochondrial adenosine triphosphate dependent potassium channels and phosphatidylinositol-dependent kinase-1.
abstract: Xenon elicits preconditioning of the myocardium via protein kinase C-epsilon. We determined the implication of (1) the mitochondrial adenosinetriphosphate dependent potassium (K(ATP)) channels and (2) the 3'phosphatidylinositol-dependent kinase-1 (PDK-1) in activating protein kinase C-epsilon. For infarct size measurements, anaesthetized rats were subjected to 25 min of coronary artery occlusion followed by 120 min of reperfusion. Rats received xenon 70% during three 5-min periods before ischaemia with or without the K(ATP) channel blocker 5-hydroxydecanoate or Wortmannin as PI3K/PDK-1 inhibitor. For Western blot, hearts were excised at five time points after xenon preconditioning (Control, 15, 25, 35, 45 min). Infarct size was reduced from 42+/-6% (mean+/-S.D.) to 27+/-8% after xenon preconditioning (P<0.05). Western blot revealed an increased activation of PKC-epsilon after 45 min and of PDK-1 after 25 min during xenon preconditioning. 5-hydroxydecanoate and Wortmannin blocked both effects. PKC-epsilon is activated downstream of mitochondrial K(ATP) channels and PDK-1. Both pathways are functionally involved in xenon preconditioning.
authors.affiliation: Department of Anaesthesiology, University Hospital of Düsseldorf, Moorenstrasse 5, 40225 Düsseldorf, Germany. N.C.Weber@amc.uva.nl
authors.forename: Nina C
authors.initials: NC
authors.lastname: Weber
authors.forename: Octavian
authors.initials: O
authors.lastname: Toma
authors.forename: Halil
authors.initials: H
authors.lastname: Damla
authors.forename: Jessica I
authors.initials: JI
authors.lastname: Wolter
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schlack
authors.forename: Benedikt
authors.initials: B
authors.lastname: Preckel
mesh_terms: D064413:3-Phosphoinositide-Dependent Protein Kinases; D000255:Adenosine Triphosphate / Q000502:physiology*; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D004789:Enzyme Activation; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism; D009203:Myocardial Infarction / Q000378:metabolism / Q000517:prevention & control; D009206:Myocardium / Q000201:enzymology* / Q000473:pathology; D015221:Potassium Channels / Q000502:physiology*; D051744:Protein Kinase C-epsilon / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D014978:Xenon / Q000494:pharmacology*
chemical_list: D018685:Anesthetics, Inhalation; D015221:Potassium Channels; D014978:Xenon; D000255:Adenosine Triphosphate; D064413:3-Phosphoinositide-Dependent Protein Kinases; D017346:Protein Serine-Threonine Kinases; D051744:Protein Kinase C-epsilon