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Effects of hypobaric hypoxia on antioxidant enzymes in rats.
Author(s) -
Nakanishi K,
Tajima F,
Nakamura A,
Yagura S,
Ookawara T,
Yamashita H,
Suzuki K,
Taniguchi N,
Ohno H
Publication year - 1995
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1995.sp021099
Subject(s) - superoxide dismutase , malondialdehyde , catalase , endocrinology , medicine , oxidative stress , hypoxia (environmental) , glutathione peroxidase , hypobaric chamber , kidney , antioxidant , glutathione , chemistry , lipid peroxidation , enzyme , biochemistry , biology , oxygen , effects of high altitude on humans , anatomy , organic chemistry
1. The present study was undertaken to investigate the effects of hypobaric hypoxia, equivalent to an altitude of 5500 m, on antioxidant enzymes in rats. 2. Malondialdehyde levels in serum, heart, lung, liver and kidney of hypobaric‐hypoxic rats were all significantly higher than in control rats by day 21 of exposure (P < 0.05), indicating increased oxidative stress. 3. Superoxide dismutase (SOD) catalyses the conversion of the superoxide anion to H2O2 and O2. The concentration of immunoreactive Mn‐SOD in the serum of hypobaric‐hypoxic rats was raised significantly from day 5 onwards, whereas in liver and lung, it had decreased significantly by day 21 (P < 0.05). 4. Glutathione peroxidase (GSH‐Px) catalyses H2O2 and certain lipid peroxides. By day 21, GSH‐Px activity had increased significantly in the heart and lungs, but decreased significantly in the liver (P < 0.05). 5. Catalase catalyses H2O2. Catalase activity in the liver and kidney of hypobaric‐hypoxic rats was significantly decreased on day 1 (P < 0.05) though levels then recovered. 6. Mn‐SOD mRNA in the liver of hypobaric‐hypoxic rats was induced during the experiment, the effect being exceptionally marked, especially during the first 3 days of exposure to hypobaric hypoxia. 7. These results suggest that the liver may be more vulnerable than the other organs tested to oxidative stress under hypobaric hypoxia.