title: Spaceflight downregulates antioxidant defense systems in rat liver.
abstract: 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 gamma-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.
authors.affiliation: Department of Kinesiology, University of Wisconsin-Madison, USA.
authors.forename: J
authors.initials: J
authors.lastname: Hollander
authors.forename: M
authors.initials: M
authors.lastname: Gore
authors.forename: R
authors.initials: R
authors.lastname: Fiebig
authors.forename: R
authors.initials: R
authors.lastname: Mazzeo
authors.forename: S
authors.initials: S
authors.lastname: Ohishi
authors.forename: H
authors.initials: H
authors.lastname: Ohno
authors.forename: L L
authors.initials: LL
authors.lastname: Ji
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D019803:Glutathione Disulfide / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013026:Space Flight; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D012333:RNA, Messenger; D008315:Malondialdehyde; D002374:Catalase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005723:gamma-Glutamyltransferase; D005982:Glutathione Transferase; D005978:Glutathione; D019803:Glutathione Disulfide