NMDA receptor antagonist felbamate reduces behavioral deficits and blood-brain barrier permeability changes after experimental subarachnoid hemorrhage in the rat

J Neurotrauma. 2007 Apr;24(4):732-44. doi: 10.1089/neu.2006.0181.

Abstract

Increased levels of glutamate and aspartate have been detected after subarachnoid hemorrhage (SAH) that correlate with neurological status. The NMDA receptor antagonist felbamate (FBM; 2-phenyl-1,3-propanediol dicarbamate) is an anti-epileptic drug that elicits neuroprotective effects in different experimental models of hypoxia-ischemia. The aim of this dose-response study was to evaluate the effect of FBM after experimental SAH in rats on (1) behavioral deficits (employing a battery of assessment tasks days 1-5 post-injury) and (2) blood-brain barrier (BBB) permeability changes (quantifying microvascular alterations according to the extravasation of protein-bound Evans Blue by a spectrophotofluorimetric technique 2 days post-injury). Animals were injected with 400 muL of autologous blood into the cisterna magna. Within 5 min, rats received daily oral administration of FBM (15, 30, or 45 mg/kg) for 2 or 5 days. Results were compared with sham-injured controls treated with oral saline or FBM (15, 30, or 45 mg/kg). FBM administration significantly ameliorated SAH-related changes in Beam Balance scores on days 1 and 2 and Beam Balance time on days 1-3, Beam Walking performance on days 1 and 2, and Body Weight on days 3-5. FBM also decreased BBB permeability changes in frontal, temporal, parietal, occipital, and cerebellar cortices; subcortical and cerebellar gray matter; and brainstem. This study demonstrates that, in terms of behavioral and microvascular effects, FBM is beneficial in a dose-dependent manner after experimental SAH in rats. These results reinforce the concept that NMDA excitotoxicity is involved in the cerebral dysfunction that follows SAH.

MeSH terms

  • Animals
  • Behavior, Animal / drug effects*
  • Blood-Brain Barrier / drug effects*
  • Body Weight / physiology
  • Cerebrovascular Circulation / drug effects
  • Dose-Response Relationship, Drug
  • Evans Blue
  • Felbamate
  • Male
  • Microcirculation / drug effects
  • Neuroprotective Agents / therapeutic use*
  • Phenylcarbamates / therapeutic use*
  • Postural Balance / drug effects
  • Propylene Glycols / therapeutic use*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors*
  • Spectrometry, Fluorescence
  • Subarachnoid Hemorrhage / drug therapy*
  • Subarachnoid Hemorrhage / physiopathology
  • Subarachnoid Hemorrhage / psychology*

Substances

  • Neuroprotective Agents
  • Phenylcarbamates
  • Propylene Glycols
  • Receptors, N-Methyl-D-Aspartate
  • Evans Blue
  • Felbamate