Reactive oxygen species precede protein kinase C-delta activation independent of adenosine triphosphate-sensitive mitochondrial channel opening in sevoflurane-induced cardioprotection.
BACKGROUND
In the current study, the authors investigated the distinct role and relative order of protein kinase C (PKC)-delta, adenosine triphosphate-sensitive mitochondrial K+ (mito K+(ATP)) channels, and reactive oxygen species (ROS) in the signal transduction of sevoflurane-induced cardioprotection and specifically addressed their mechanistic link.


METHODS
Isolated rat trabeculae were preconditioned with 3.8% sevoflurane and subsequently subjected to an ischemic protocol by superfusion of trabeculae with hypoxic, glucose-free buffer (40 min) followed by 60 min of reperfusion. In addition, the acute affect of sevoflurane on PKC-delta and PKC-epsilon translocation and nitrotyrosine formation was established with use of immunofluorescent analysis. The inhibitors chelerythrine (6 microM), rottlerin (1 microM), 5-hydroxydecanoic acid sodium (100 microM), and n-(2-mercaptopropionyl)-glycine (300 microM) were used to study the particular role of PKC, PKC-delta, mito K+(ATP), and ROS in sevoflurane-related intracellular signaling.


RESULTS
Preconditioning of trabeculae with sevoflurane preserved contractile function after ischemia. This contractile preservation was dependent on PKC-delta activation, mito K+(ATP) channel opening, and ROS production. In addition, on acute stimulation by sevoflurane, PKC-delta but not PKC-epsilon translocated to the sarcolemmal membrane. This translocation was inhibited by PKC inhibitors and ROS scavenging but not by inhibition of mito K+(ATP) channels. Furthermore, sevoflurane directly induced nitrosylation of sarcolemmal proteins, suggesting the formation of peroxynitrite.


CONCLUSIONS
In sevoflurane-induced cardioprotection, ROS release but not mito K+(ATP) channel opening precedes PKC-delta activation. Sevoflurane induces sarcolemmal nitrotyrosine formation, which might be involved in the recruitment of PKC-delta to the cell membrane.
Bouwman
R Arthur
RA
Department of Anesthesiology and the Laboratory for Physiology, Vrije Universiteit Medical Center-Institute for Cardiovascular Research Vrije Universiteit, Amsterdam, The Netherlands.
Musters
René J P
RJ
van Beek-Harmsen
Brechje J
BJ
de Lange
Jaap J
JJ
Boer
Christa
C
D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D006321:Heart / Q000187:drug effects; D006331:Heart Diseases / Q000517:prevention & control*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D008565:Membrane Proteins / Q000187:drug effects / Q000378:metabolism*; D008738:Methyl Ethers / Q000494:pharmacology*; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D009200:Myocardial Contraction / Q000187:drug effects; D015221:Potassium Channels; D011493:Protein Kinase C / Q000378:metabolism*; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D008565:Membrane Proteins; D008738:Methyl Ethers; D015221:Potassium Channels; D017382:Reactive Oxygen Species; C117780:mitochondrial K(ATP) channel; D000077149:Sevoflurane; C497260:Prkcd protein, rat; C497257:Prkce protein, rat; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon