Effect of long-term exposure to cold on the antioxidant defense system in the rat.
Catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), and glutathione-S-transferase (GST) activities as well as glutathione (GSH), ascorbic acid (AsA), and vitamin E concentrations were analyzed in the blood, liver, brain, interscapular brown adipose tissue (IBAT), and small intestine of rats exposed to low environmental temperature (4 degrees C; 35, 75, and 105 d of exposure) and in controls of the same age exposed to an environmental temperature of 22 +/- 2 degrees C. Prolonged cold exposure resulted in an increase in GSH-Px in IBAT and in small intestine after 35, 75, and 105 d of exposure. Catalase activity in cold-exposed animals was higher in IBAT after 75 and 105 d of cold exposure. Glutathione reductase activity was greater in brain after 35 d, in liver after 75 d, and in IBAT after 105 d of exposure to low temperatures as compared to the controls. In contrast, GST activity was lower in liver and IBAT after 35 and 75 d of cold exposure. AsA and GSH (determined only 105 d after cold exposure) were markedly higher in IBAT, whereas plasma GSH was lower and plasma AsA was higher in cold-exposed animals. The observed changes in analysed components of the antioxidant defense system under conditions of prolonged exposure to low temperature suggest that a reorganization the activity of this system at the molecular level occurred. Although other studies indicate that a 21-d cold exposure is sufficient for adaptation of thermogenesis, the present study shows that in general, longer periods are required for the registration of the changes in the antioxidant defense system.
Spasić
M B
MB
Institute for Biological Research, University of Belgrade, Serbia.
Saicić
Z S
ZS
Buzadzić
B
B
Korać
B
B
Blagojević
D
D
Petrović
V M
VM
D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D000975:Antioxidants; D001205:Ascorbic Acid / Q000097:blood / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D002374:Catalase / Q000097:blood / Q000378:metabolism*; D003080:Cold Temperature; D005978:Glutathione / Q000097:blood / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000097:blood / Q000378:metabolism; D005980:Glutathione Reductase / Q000097:blood / Q000378:metabolism; D005982:Glutathione Transferase / Q000097:blood / Q000378:metabolism; D007421:Intestine, Small / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014810:Vitamin E / Q000097:blood / Q000378:metabolism*
D000975:Antioxidants; D014810:Vitamin E; D002374:Catalase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005978:Glutathione; D001205:Ascorbic Acid