Neuroprotective effects of the glutamate release inhibitor 619C89 in temporary middle cerebral artery occlusion.

619C89 is a use-dependent Na+ channel antagonist that decreases the release of glutamate during ischemia. The efficacy of this drug in reducing infarction volume 72 h after occlusion of the middle cerebral artery (MCA) for 2 h in rats (n = 93) was determined by analysis of TTC-stained coronal section of the brain. Doses of 10, 20, 30 and 50 mg/kg of study drug given i.v. prior to MCA occlusion significantly (P < 0.05-0.01) reduced infarction volume in cortex compared to vehicle controls. Only the 50 mg/kg dose reduced infarction volume in the striatum (P < 0.05). Administration of 50 mg/kg of 619C89 30 and 60 min after the onset of ischemia reduced cortical infarction volume (P < 0.05), but there was no effect when the drug was given 5 min after reperfusion. No post-treatment regimen reduced striatal infarction volume. These results confirm the neuroprotective effects of 619C89 in temporary focal ischemia.