Effects of Normobaric Hyperoxia in a Rat Model of Focal Cerebral Ischemia—Reperfusion
Open Access
- 1 July 2002
- journal article
- research article
- Published by SAGE Publications in Journal of Cerebral Blood Flow & Metabolism
- Vol. 22 (7), 861-868
- https://doi.org/10.1097/00004647-200207000-00011
Abstract
Recent studies suggest that normobaric hyperoxia can be beneficial, if administered during transient stroke. However, increased oxygenation theoretically may increase oxygen free-radical injury, particularly during reperfusion. In the present study, the authors assessed the benefit and risks of hyperoxia during focal cerebral ischemia and reperfusion. Rats were subjected to hyperoxia (Fio2 100%) or normoxia (Fio2 30%) during 2-hour filament occlusion and 1-hour reperfusion of the middle cerebral artery. At 24 hours, the hyperoxia group showed 70% (total) and 92% (cortical) reduction in infarct volumes as compared to the normoxia group. Levels of oxidative stress were evaluated using three indirect methods. First, since oxygen free radicals increase blood—brain barrier (BBB) damage, Evan's blue dye extravasation was quantified to assess BBB damage. Second, the expression of heme oxygenase-1 (HO-1), a heat shock protein inducible by oxidative stress, was assessed using Western blot techniques. Third, an immunoblot technique (“OxyBlot”) was used to assess levels of protein carbonyl formation as a marker of oxidative stress—induced protein denaturation. At 24 hours, Evan's blue dye extravasation per average lesion volume was similar between groups. There were no significant differences in HO-1 induction and protein carbonyl formation between groups, in the ipsilateral or contralateral hemispheres, at 6 hours and at 24 hours. These results indicate that hyperoxia treatment during focal cerebral ischemia—reperfusion is neuroprotective, and does not increase oxidative stress.Keywords
This publication has 36 references indexed in Scilit:
- Hypoxia, hyperoxia, ischemia, and brain necrosisNeurology, 2000
- Should Stroke Victims Routinely Receive Supplemental Oxygen?Stroke, 1999
- Hyperbaric Oxygen in the Treatment of Acute Ischemic StrokeStroke, 1995
- A pilot study of hyperbaric oxygen in the treatment of human stroke.Stroke, 1991
- Free radical production and ischemic brain damage: Influence of postischemic oxygen tensionInternational Journal of Developmental Neuroscience, 1991
- Reversible middle cerebral artery occlusion without craniectomy in rats.Stroke, 1989
- Quantitative Evaluation of Vascular Permeability in the Gerbil Brain after Transient Ischemia Using Evans Blue FluorescenceJournal of Cerebral Blood Flow & Metabolism, 1988
- Hyperbaric oxygen and cerebral infarction in the gerbilSurgical Neurology, 1987
- Breathing 100% oxygen after global brain ischemia in Mongolian Gerbils results in increased lipid peroxidation and increased mortality.Stroke, 1987
- Cerebral Vasomotor Responsiveness During 100% Oxygen Inhalation in Cerebral IschemiaArchives of Neurology, 1983