Effect of riluzole on focal cerebral ischemia in rats.

The effects of riluzole, a putative inhibitor of glutamate release, on the histological and neurobehavioral consequences of middle cerebral artery occlusion were tested in Sprague-Dawley rats. Neurobehavioral studies (neurological examination, passive avoidance task) were carried out with sham-operated and occluded rats. Riluzole 4 and 8 mg/kg administered 30 min after occlusion reduced (P < 0.01) the cortical infarct (respectively 94 +/- 12 mm3 and 73 +/- 15 mm3 versus 139 +/- 8 mm3 for control rats). Striatum necrosis was not modified by the low dosage (46 +/- 3 mm3 versus 49 +/- 3 mm3 for control rats), whereas the high dosage increased it (61 +/- 3 mm3, P < 0.05). The ischemia-induced neurological and memory impairments were not improved by riluzole. Our results indicate that a drug depressing glutamatergic neurotransmission without blocking the glutamate receptors exerts anti-ischemic activity. Moreover, the results highlight the need for carrying out histological and neurobehavioral studies in parallel in this model.