DETECTION OF HYDROXYL RADICALS IN RAT STRIATUM DURING TRANSIENT FOCALCEREBRAL-ISCHEMIA - POSSIBLE IMPLICATION IN TISSUE-DAMAGE

As increasing arguments suggest that the reperfusion phase following a n ischemic insult may aggravate tissue injury by yielding hydroxyl rad icals ((OH)-O-.), we examined whether these oxyradicals are generated in rat striatum during transient focal cerebral ischemia. (OH)-O-. wer e detected in dialysate samples by intrastriatal microdialysis coupled with the technique of salicylate hydroxylation. Ischemia was achieved by tandem occlusion of the left middle cerebral artery and common car otid arteries (45 min) followed by reperfusion. An (OH)-O-. formation occurred both during ischemia and early reperfusion. Additionally, the volume of the striatal infarct induced by ischemia correlated positiv ely with the amount of (OH)-O-. produced during ischemia and reperfusi on. Taken together, these results provide evidence of the formation of cytotoxic (OH)-O-. in rat striatum which might participate in the isc hemic injury of this structure.