Antioxidant responses to chronic hypoxia in the rat cerebellum and pons.

TitleAntioxidant responses to chronic hypoxia in the rat cerebellum and pons.
Publication TypeJournal Article
Year of Publication2005
AuthorsRamanathan, L, Gozal D, Siegel JM
JournalJournal of neurochemistry
Volume93
Issue1
Pagination47-52
Date Published2005 Apr
ISSN0022-3042
KeywordsAnimals, Anoxia, Antioxidants, Brain Chemistry, Cerebellum, Chronic Disease, Disease Models, Animal, Glutathione, Glutathione Reductase, Lipid Peroxidation, Male, pons, Random Allocation, Rats, Rats, Sprague-Dawley, Superoxide Dismutase, Thiobarbituric Acid Reactive Substances, Time Factors
Abstract

Obstructive sleep apnea (OSA) is characterized by chronic intermittent hypoxia (CIH) and sleep fragmentation and deprivation. Exposure to CIH results in oxidative stress in the cortex, hippocampus and basal forebrain of rats and mice. We show that sustained and intermittent hypoxia induces antioxidant responses, an indicator of oxidative stress, in the rat cerebellum and pons. Increased glutathione reductase (GR) activity and thiobarbituric acid reactive substance (TBARS) levels were observed in the pons and cerebellum of rats exposed to CIH or chronic sustained hypoxia (CSH) compared with room air (RA) controls. Exposure to CIH or CSH increased GR activity in the pons, while exposure to CSH increased the level of TBARS in the cerebellum. The level of TBARS was increased to a greater extent after exposure to CSH than to CIH in the cerebellum and pons. Increased superoxide dismutase activity (SOD) and decreased total glutathione (GSHt) levels were observed after exposure to CIH compared with CSH only in the pons. We have previously shown that prolonged sleep deprivation decreased SOD activity in the rat hippocampus and brainstem, without affecting the cerebellum, cortex or hypothalamus. We therefore conclude that sleep deprivation and hypoxia differentially affect antioxidant responses in different brain regions.

Alternate JournalJ. Neurochem.