Effects of 30d Simulated Weightlessness on Antioxidant Defense System in Rat Liver
- Paper number
IAC-06-A1.4.04
- Author
Dr. Wu Bin, Astronaut Center of China, China
- Coauthor
Mr. Ping Wu, Astronaut Center of China, China
- Year
2006
- Abstract
Background: There is little knowledge about effects of spaceflight, especially long-term spaceflight on body’s antioxidant defense system. And antioxidant defense system plays an important role of protecting body against free radical attack. There are some reasons for suspecting that antioxidant defense system may be damaged with spaceflight.
Purpose: The purpose of the present study was to investigate effects of weightlessness included in long-term spaceflight on antioxidant defense system and briefly to evaluate its potent consequences.
Methods: Our experiment was designed on basis of summarizing and analyzing a few literatures in this field. Tail-suspension for 30 d was used to simulate long-term weightlessness. Thirty-two male Sprague-Dawley rats were randomly divided into control, 30 d suspension, 1 d recovery and 7 d recovery group and each group included 8 rats. Lipid peroxidation, contents of antioxidants and activities of antioxidant enzymes in rat liver were measured. Abundances of mRNA for some antioxidant enzymes were quantificationally determined by Northern blot.
Results: Compared with control group, liver malondialdehyde (MDA) and hydroperoxide (LOOH) contents showed an increasing trend (P<0.10) or significantly increased (P<0.05), while glutathione (GSH) and total GSH concentration dramatically decreased (P<0.05 or 0.01) in suspension group and 1 d recovery group. Activities of glutathione peroxidase (GSH-Px) and catalase showed a downtrend (P<0.10) or significantly decreased (P<0.05). The relative abundance of mRNA for Cu-Zn superoxide dismutase (Cu-Zn SOD) and GSH-Px was markedly decreased (P<0.05). These changes induced by suspension did not completely come back to control level in 7 d recovery group. In addition, the changing magnitude of above indexes was largest for 1 d recovery group among experimental groups.
Conclusion: Long time weightlessness may injure antioxidant defense system and caused oxidative stress and damage. These effects are more significant when rats move from weightlessness to gravity environment. It is suggested that potent harm to astronauts’ health induced by wakened antioxidant defense system should be considered in long-term spaceflight, especially in future trip to Mars. At last, author think it is of importance to deepen concerned research and bring forward attempt directions.
- Abstract document
- Manuscript document
IAC-06-A1.4.04.pdf (🔒 authorized access only).
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