Effect of Allopurinol on Brain Infarction Following Middle Cerebral Artery Occlusion in Rats

ABSTRACT

Of the many potential source of free radial generation, the enzyme xanthine oxidase has been shown to be important in ischemia in non-cerebral tissues. Oxygen-derived free radicals have been implicated in various pathological conditions including ischemia. Xanthine oxidase serve as a source of oxidizing agents such as superoxide radical and hydrogen peroxide. It is investigated that the effect of a specific xanthine oxidase inhibitor, allopurinol, on infarct size in a model of continuous partial cerebral ischemia in rats. Infarct volume was measured by triphenyl tetrazolium chloride staining of brains removed 24 hours after middle cerebral arterial occlusion. Cortical tissue was more effectively protected than basal tissue, especially in allopurinol pretreated group. On histological examinations, hemispheric swelling, PMN cell infiltration and endothelial damage were noted irrespective of allopurinol treatment. It was speculated that free radicals are important in infarction secondary to partial continuous cerebral ischemia and that xanthine oxidase may by the primary source of these radicals.