Effect of Normobaric Hyperoxia Preconditioning on VEGF and Endostatin Levels in the Rat Stroke Model

Abstract

Stroke is the second leading cause of death worldwide. It is also the second rationale of disability, after Dementia. Interestingly, pre-conditioning can have a beneficial effect on stroke that increases ischemic tolerance in tissues. In this paper, we have shown that normobaric hyperoxia (HO) protects the rat brain from ischemia injury by changing in VEGF and endostatin levels. Animals were divided into three groups: the first group was exposed to 95% oxygen for 4 hours for 6 days, the second group was in room air, and the third group was sham. MCAO-operated were subjected to 60 minutes of MCAO. After 2 days from pre-treatment and 24 hours reperfusions, neurologic deficit score (NDS) and infarct volume (IV) were evaluated. We have measured VEGF and Endostatin levels of core, penumbra and sub-cortex regions. Pre-conditioning with HO decreased NDS (p<0.002) and IV (p<0.019). Our data indicated that VEGF levels were increased in core and penumbra areas (p<0.000, 0.015, respectively) and Endostatin levels were reduced in penumbra, sub cortex and core of HO subgroups (p<0.004, 0.007, 0.000, respectively). Although further studies are needed to clarify ischemic tolerance induced by HO, alterations of VEGF and Endostatin levels may have a role in neuroprotective effects.