Spaceflight Downregulates Antioxidant Defense Systems in Rat Liver

• Published in: Free radical biology & medicine 1998-01, Vol.24 (2), p.385-390
• Main Authors: Hollander, J., Gore, M., Fiebig, R., Mazzeo, R., Ohishi, S., Ohno, H., Ji, L.L.
• Format: Article
• Language: English
• Subjects: Animals; Antioxidant enzyme; Antioxidants - metabolism; Catalase - genetics; Catalase - metabolism; gamma-Glutamyltransferase - metabolism; Glutathione; Glutathione - metabolism; Glutathione Disulfide - metabolism; Glutathione Reductase - metabolism; Glutathione Transferase - metabolism; Lipid peroxidation; Liver; Liver - metabolism; Male; Malondialdehyde - metabolism; Rat; Rats; Rats, Sprague-Dawley; RNA, Messenger - metabolism; Space Flight; Space life sciences; Spaceflight; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/S0891-5849(97)00278-5

Liver antioxidant enzyme activities, mRNA abundance, and glutathione (GSH) status were investigated in male Sprague-Dawley rats placed in an enclosure module aboard Space Shuttle STS-63 for 8 d (F, n = 6). F animals were compared to rats housed in an enclosure module on the ground (G, n = 9), which simulated the vibration and temperature conditions associated with launch and flight, and rats kept under conventional ground vivarium conditions in individual cages (V, n = 6). Spaceflight significantly decreased catalase, GSH reductase, and GSH sulfur-transferase activities in the liver ( p < .05). Neither enzyme activity nor enzyme protein content of Cu-Zn and Mn superoxide dismutase (SOD) was affected by flight. The relative abundance of mRNA for Cu-Zn SOD and catalase was significantly decreased comparing F with G rats ( p < .05). Spaceflight resulted in a dramatic decrease of liver GSH, glutathione disulfide, and total GSH contents ( p < .01), which were accompanied by a lower γ-glutamyl transpeptidase activity ( p < .05). F rats showed a 47% ( p < .05) increase in liver malondialdehyde concentration compared to G and V rats. Liver protein content was not affected by flight. These results indicate that spaceflight can downregulate antioxidant defense capacity and elicit an oxidative stress in the liver.