RT Journal Article SR Electronic T1 Effects of a Novel Free Radical Scavenger, MCI-186, on Ischemic Brain Damage in the Rat Distal Middle Cerebral Artery Occlusion Model JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 921 OP 927 VO 281 IS 2 A1 Kawai, Hiroshi A1 Nakai, Hiroshi A1 Suga, Misao A1 Yuki, Satoshi A1 Watanabe, Toshiaki A1 Saito, Ken-Ichi YR 1997 UL http://jpet.aspetjournals.org/content/281/2/921.abstract AB We investigated the effects of a free radical scavenger, 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), on infarct areas, neurological deficits and regional cerebral blood flow (rCBF), with use of a rat thrombotic distal middle cerebral artery (dMCA) occlusion model to elucidate its possible therapeutic effects on focal cerebral ischemia. In addition, we have attempted to measure 2-oxo-3-(phenylhydrazono)-butanoic acid (OPB), which is the major oxidation product of MCI-186, in the penumbral cortex of a thrombotic dMCA occlusion model. Postischemic treatment with MCI-186 (3 mg/kg) significantly (P < .05) decreased the size of the cerebral infarcts 1 day after dMCA occlusion. MCI-186 (3 mg/kg) significantly (P < .05) improved the neurological deficits 1 day after dMCA occlusion. On the contrary, MCI-186 had no effect on rCBF 1 day after dMCA occlusion. MCI-186 mainly reacted into OPB by peroxidation in rat brain homogenates. Furthermore, the increase in OPB content in the ischemic penumbral cortex tissue was confirmed after 90 min of MCI-186 perfusion. These results suggest that MCI-186 has a protective effect on brain ischemia by reacting with oxygen radicals and that oxygen radicals are closely related to postischemic brain injury. The American Society for Pharmacology and Experimental Therapeutics