Hyperoxia with 100% oxygen following hypoxia-ischemia increases brain damage in newborn rats

• Published in: Biology of the neonate Vol. 88; no. 3; pp. 168 - 171
• Main Authors: Shimabuku, Roberto, Ota, Arturo, Pereyra, Sonia, Véliz, Betty, Paz, Edith, Nakachi, Graciela, More, Mario, Oliveros, Miguel
• Format: Journal Article
• Language: English
• Published: Switzerland S. Karger AG 01.01.2005
• Subjects: Animals; Animals, Newborn; Carotid Arteries; Cerebral Cortex - pathology; Hippocampus - pathology; Hyperoxia - complications; Hypoxia, Brain - etiology; Hypoxia, Brain - pathology; Hypoxia-Ischemia, Brain - complications; Ligation; Oxygen - administration & dosage; Oxygen - adverse effects; Rats
• ISSN: 0006-3126; 1661-7800; 1661-7819; 1421-9727
• DOI: 10.1159/000086206

To describe the effect of reoxygenation with 100% O2 as compared to the effect of room air in newborn rat brains after asphyxia. Experimental asphyxia (carotid artery ligation followed by hypoxic exposure with 8% O2 for 2 h) was performed on 7-day-old rats. After hypoxia-ischemia the rats were reoxygenated with either 100% O2 (hyperoxia group) or 21% O2 (room air group) for 24 h and then returned to the dam. The rats were killed 1 week after the experiment to study the cerebral cortex and hippocampus. Rats reoxygenated with 100% O2 post-asphyxia showed more frequency of cortical damage (10 of 24 rats) than those reoxy genated with room air (3 of 24 rats) (chi2 test, p = 0.02). We consider that hyperoxia with 100% oxygen after hypoxia-ischemia can cause more damage in the cerebral cortex than room air in newborn rats.