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Antioxidant effects of melatonin in rats during chronic exposure to hyperbaric oxygen.
- Source :
-
Journal of pineal research [J Pineal Res] 2007 Jan; Vol. 42 (1), pp. 50-4. - Publication Year :
- 2007
-
Abstract
- In addition to its beneficial effects, hyperbaric oxygen (HBO) exposure causes some detrimental effects via oxidative stress. Previous experimental studies showed that melatonin is a useful agent to block single session HBO-induced oxidative stress. In the present study, we investigated the antioxidant effect of exogenously administered as well as endogenously produced melatonin in lung and brain tissues of rats exposed to long term HBO. The HBO procedure was set as daily exposures to 2.5 ATA of oxygen for 1 hr and a total of 10 sessions. Twenty-eight male Sprague-Dawley rats were divided into four groups as follows: control, daytime HBO, daytime HBO plus melatonin (5 mg/kg), nighttime HBO. Tissue oxidative/antioxidant status was examined by determining the protein carbonyl content as a criteria for oxidative stress and the activities of the antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). HBO exposure for 10 days caused significant increases in protein carbonyl content and SOD levels of lung and brain, but GSH-Px activities remained unaffected. The increases in protein carbonyls were blocked by exogenously administered melatonin and in part by nighttime exposure to darkness whereas the increase of SOD activity was only impeded by endogenously produced melatonin in brain tissue. Lung SOD activity was augmented by endogenous melatonin. In conclusion, melatonin blocks long-term HBO-induced cumulative oxidative stress as indicated changes in protein carbonyls. Both exogenously injected and physiologically secreted melatonin has this potential. The effects of HBO-exposure and melatonin on the activities of the antioxidative enzymes are less clear.
- Subjects :
- Animals
Brain drug effects
Glutathione Peroxidase drug effects
Lung drug effects
Male
Protein Carbonylation drug effects
Rats
Rats, Sprague-Dawley
Superoxide Dismutase drug effects
Antioxidants pharmacology
Hyperbaric Oxygenation adverse effects
Melatonin pharmacology
Oxidative Stress drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0742-3098
- Volume :
- 42
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Journal of pineal research
- Publication Type :
- Academic Journal
- Accession number :
- 17198538
- Full Text :
- https://doi.org/10.1111/j.1600-079X.2006.00382.x