Antioxidant CR-6 protects against reperfusion injury after a transient episode of focal brain ischemia in rats

J Cereb Blood Flow Metab. 2010 Mar;30(3):638-52. doi: 10.1038/jcbfm.2009.237. Epub 2009 Nov 11.

Abstract

Oxidative and nitrosative stress are targets for intervention after ischemia/reperfusion. The aim of this study was to explore the effect of CR-6, a vitamin-E analogue that is antioxidant and scavenger of nitrogen-reactive species. Sprague-Dawley rats had the middle cerebral artery (MCA) occluded either for 90 mins or permanently. Cortical perfusion was continuously monitored by laser-Doppler flowmetry. CR-6 (100 mg/kg) was administered orally either at 2 and 8 h after MCA occlusion, or at 2 h only. Infarct volume, neurological deficit, and signs of reperfusion injury were evaluated. CR-6 was detected in plasma and brain by HPLC. CR-6 reduced glutathione consumption in the ischemic brain and superoxide generation in the isolated MCA. CR-6 decreased infarct volume and attenuated the neurological deficit at 1 and 7 days after ischemia/reperfusion, but not after permanent ischemia. Immediately after reperfusion, cortical blood flow values returned to their baseline (+/-20%) in several animals, whereas others showed hyper-perfusion (>20% of baseline). Reactive hyperemia was associated with adverse events such as increased cortical BBB leakage, edema, protein nitrotyrosination, COX-2 expression, and neutrophil accumulation; and with a poorer outcome, and CR-6 attenuated these effects. In conclusion, oral CR-6 administration after transient ischemia protects the brain from reperfusion injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / pharmacology*
  • Benzopyrans / pharmacology*
  • Blood-Brain Barrier / drug effects
  • Blood-Brain Barrier / physiology
  • Blotting, Western
  • Brain Edema / pathology
  • Brain Edema / prevention & control
  • Brain Ischemia / drug therapy*
  • Brain Ischemia / pathology
  • Cerebral Infarction / pathology
  • Cerebrovascular Circulation / physiology
  • Cyclooxygenase 2 / metabolism
  • Hyperemia / blood
  • Immunohistochemistry
  • Infarction, Middle Cerebral Artery / pathology
  • Inflammation / pathology
  • Leukocytes / pathology
  • Male
  • Neuroprotective Agents*
  • Neutrophil Infiltration
  • Oxidative Stress / drug effects
  • Psychomotor Performance / physiology
  • RNA / biosynthesis
  • RNA / isolation & purification
  • Rats
  • Rats, Sprague-Dawley
  • Reactive Nitrogen Species / metabolism
  • Reperfusion Injury / pathology
  • Reperfusion Injury / prevention & control*

Substances

  • Antioxidants
  • Benzopyrans
  • CR 6
  • Neuroprotective Agents
  • Reactive Nitrogen Species
  • RNA
  • Cyclooxygenase 2