Protein kinase C delta modulates endothelial nitric oxide synthase after cardiac arrest

J Cereb Blood Flow Metab. 2014 Apr;34(4):613-20. doi: 10.1038/jcbfm.2013.232. Epub 2014 Jan 22.

Abstract

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arginine / pharmacology
  • Blood Flow Velocity / drug effects
  • Blood Flow Velocity / physiology*
  • Cerebral Cortex / blood supply*
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / enzymology
  • Cerebrovascular Circulation / drug effects
  • Cerebrovascular Circulation / physiology*
  • Enzyme Inhibitors / pharmacology
  • Heart Arrest / enzymology*
  • Heart Arrest / physiopathology
  • Laser-Doppler Flowmetry
  • Male
  • Microscopy, Confocal
  • Nitric Oxide Donors / pharmacology
  • Nitric Oxide Synthase Type III / antagonists & inhibitors
  • Nitric Oxide Synthase Type III / metabolism*
  • Nitrites / blood
  • Oligopeptides / pharmacology
  • Protein Kinase C-delta / antagonists & inhibitors*
  • Rats
  • Rats, Sprague-Dawley
  • Substrate Specificity

Substances

  • Enzyme Inhibitors
  • Nitric Oxide Donors
  • Nitrites
  • Oligopeptides
  • Ser-Phe-Asn-Ser-Tyr-Glu-Leu-Gly-Glu-Ser-Leu
  • Arginine
  • Nitric Oxide Synthase Type III
  • Nos3 protein, rat
  • Protein Kinase C-delta