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Background and Aims It was found that inhibition of xanthine oxidase are accompanied by anti-ischemic and neuroprotective effects in the experiment and clinic.

Methods The study of cerebral ischemia in the experiment was carried out on 4 groups of outbred rats: I- sham-operated - control, II- ligation of the left carotid artery without additional intervention, III- administration of allopurinol before ligation of the carotid artery, IV- ligation of the carotid artery + administration of allopurinol 1 hour after surgery.

Results In a histological examination of brain preparations made in the frontal plane at the level of the mid-central part, covering both cortical and other structures, 5 μm thick, stained with hematoxylin-eosin, in animals of group I the following morphological picture was observed: there were no significant differences in both halves of the brain. In rats of group II, zones of damage to the nervous tissue were found in the cortex on the side of occlusion. No clear architectural division into cortical plates was recorded. In group IV, the changes were identical to group II. When studying brain slices in rats of group III, the degree of alterative disorders was less pronounced compared to groups II and IV. This was expressed both in a smaller area of damaged areas and in a relatively smaller number of cortical cells subjected to deep degeneration, meaning pyknotically wrinkled with eosinophilic cytoplasm. In addition, none of the animals in this group had perivascular hemorrhages or leukodiapedesis.

Conclusions Preliminary inhibition of xanthine oxidase before modeling experimental ischemia, has neuroprotective effects.