Protein kinase C delta modulates endothelial nitric oxide synthase after cardiac arrest.
We previously showed that inhibition of protein kinase C delta (PKCδ) improves brain perfusion 24 hours after asphyxial cardiac arrest (ACA) and confers neuroprotection in the cortex and CA1 region of the hippocampus 7 days after arrest. Therefore, in this study, we investigate the mechanism of action of PKCδ-mediated hypoperfusion after ACA in the rat by using the two-photon laser scanning microscopy (TPLSM) to observe cortical cerebral blood flow (CBF) and laser Doppler flowmetry (LDF) detecting regional CBF in the presence/absence of δV1-1 (specific PKCδ inhibitor), nitric oxide synthase (NOS) substrate (L-arginine, L-arg) and inhibitor (N(ω)-Nitro-L-arginine, NLA), and nitric oxide (NO) donor (sodium nitroprusside, SNP). There was an increase in regional LDF and local (TPLSM) CBF in the presence of δV1-1+L-arg, but only an increase in regional CBF under δV1-1+SNP treatments. Systemic blood nitrite levels were measured 15 minutes and 24 hours after ACA. Nitrite levels were enhanced by pretreatment with δV1-1 30 minutes before ACA possibly attributable to enhanced endothelial NOS protein levels. Our results suggest that PKCδ can modulate NO machinery in cerebral vasculature. Protein kinase C delta can depress endothelial NOS blunting CBF resulting in hypoperfusion, but can be reversed with δV1-1 improving brain perfusion, thus providing subsequent neuroprotection after ACA.
Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami, Miller School of Medicine, Two Story Laboratory (TSL), Medical Campus, Miami, Florida, USA.
Hung Wen
HW
Lin
Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami, Miller School of Medicine, Two Story Laboratory (TSL), Medical Campus, Miami, Florida, USA.
Victoria L
VL
Gresia
Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami, Miller School of Medicine, Two Story Laboratory (TSL), Medical Campus, Miami, Florida, USA.
Holly M
HM
Stradecki
Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami, Miller School of Medicine, Two Story Laboratory (TSL), Medical Campus, Miami, Florida, USA.
Aleksey
A
Alekseyenko
Department of Critical Care Medicine, Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Cameron
C
Dezfulian
Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami, Miller School of Medicine, Two Story Laboratory (TSL), Medical Campus, Miami, Florida, USA.
Jake T
JT
Neumann
Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami, Miller School of Medicine, Two Story Laboratory (TSL), Medical Campus, Miami, Florida, USA.
Kunjan R
KR
Dave
Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami, Miller School of Medicine, Two Story Laboratory (TSL), Medical Campus, Miami, Florida, USA.
Miguel A
MA
Perez-Pinzon
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology*; D002540:Cerebral Cortex / Q000098:blood supply* / Q000187:drug effects / Q000201:enzymology; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006323:Heart Arrest / Q000201:enzymology* / Q000503:physiopathology; D017078:Laser-Doppler Flowmetry; D008297:Male; D018613:Microscopy, Confocal; D020030:Nitric Oxide Donors / Q000494:pharmacology; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009573:Nitrites / Q000097:blood; D009842:Oligopeptides / Q000494:pharmacology; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013379:Substrate Specificity
D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D009573:Nitrites; D009842:Oligopeptides; C477270:Ser-Phe-Asn-Ser-Tyr-Glu-Leu-Gly-Glu-Ser-Leu; D001120:Arginine; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D051745:Protein Kinase C-delta