The role of oxygen radicals-scavenger in neuroprotection-induced by normobaric hyperoxia on infarct volume in the rat brain

Objective: Recent studies have shown that the use of prolonged and intermittent normobaric hyperoxia (95%) decrease the infarct volume of stroke. The aim of current study was to study the effect of an oxygen radicals-scavenger applied during intermittent normobaric hyperoxia on infarct volume in the rat brain and neurologic deficit.
Materials and Methods: Male Wistar rats (250-350 g) were divided to two main groups. These groups were respectively subjected to room air (21% O2; RA) or normobaric hyperoxia (95% O2; HO) 4 hours per day for 6 days. Each main group was divided to three subgroups which received nothing (RA and HO), normal saline (HO-S and RA-S) or Dimethyltiourea (HO-MT and RA-MT. Afterward, all rats were subjected to 60 min middle cerebral artery occlusion (MCAO). After 24 h, neurologic deficit scores and infarct volume were assessed.
Results: The medians of neurologic deficit scores in RA, RA-MT, RA-S, HO-MT, HO-S, and HO were 2, 2, 2, 2, 0, 0, respectively. The infarct volume in RA, RA-MT, RA-S, and HO-MT versus HO-S, and HO were increased. Above results showed that neurologic deficit score and infarct volume were restored by MT significantly.
Conclusion: The effective neuroprotection induced by intermittent normobaric hyperoxia seems to be mediated at least partially by oxygen radicals.