Normobaric oxygen for cerebral ischemic injury.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Physiology

Background:

• Cerebral ischemia/reperfusion injury causes neural cell damage.
• Normobaric oxygen (NBO) offers rapid, non-invasive therapeutic potential for ischemic/hypoxic diseases.
• Hyperbaric oxygen may exacerbate oxidative stress, unlike NBO.

Purpose of the Study:

• To investigate the therapeutic effects of normobaric oxygen pretreatment on focal cerebral ischemia in a rat model.
• To elucidate the underlying molecular mechanisms, particularly the role of the hypoxia-inducible factor (HIF) pathway.

Main Methods:

• Rats underwent 6 days of normobaric oxygen (95% O2) pretreatment before focal cerebral ischemia induction.
• Neurological deficits were assessed using behavioral studies and Nissl/TTC staining.
• Expression levels of HIF-1α, Notch-1, VEGF, and EPO were analyzed via immunohistochemistry and Western blot.
• The effect of a HIF inhibitor (2-methoxyestradiol) was evaluated.

Main Results:

• Normobaric oxygen pretreatment significantly improved neurological deficits and reduced infarct volume.
• Increased expression of HIF-1α, Notch-1, vascular endothelial growth factor (VEGF), and erythropoietin (EPO) was observed.
• Inhibition of HIF-1α suppressed the neuroprotective effects of NBO pretreatment.

Conclusions:

• Normobaric oxygen pretreatment demonstrates a protective effect against cerebral ischemic injury in rats.
• The hypoxia-inducible factor signal pathway plays a crucial role in mediating these protective effects.
• NBO represents a promising non-invasive therapeutic strategy for ischemic stroke.