Inhibitory effect of MCI-186, a free radical scavenger, on cerebral ischemia following rat middle cerebral artery occlusion.

1. In this study, we investigated the effect of a radical scavenger, MCI-186 (3-methyl-1-phenyl-2-pyrazolin-5-one), on cerebral damage induced by rat middle cerebral artery (MCA) occlusion, and further measured the hydroxyl radical level at the ischemic border zone using a microdialysis technique. 2. MCI-186, at a dose of 3 mg/kg per 30 min, was administered as a continuous infusion two times for 30 min, starting 20 min and then 80 min after Rose Bengal injection. 3. MCI-186 significantly (P < 0.05) reduced size of cerebral damage 24 hr after MCA occlusion and significantly (P < 0.05) reduced hydroxyl radical level.