Aging affects but does not eliminate the enzymatic antioxidative response to hypoxia/reoxygenation in cerebral cortex.
The effect of aging on basal and hypoxia/reoxygenation levels of both oxidative stress (protein carbonyl and TBARS) and antioxidative-enzyme activity (Cu/Zn-SOD; Mn-SOD; Catalase, CAT; Se-independent and Se-dependent glutathione peroxidase, GPX; glutathione transferase, GST and glutathione reductase, GR) has been studied in the cerebral cortex of adult and old rats. Oxidative stress markers increased with aging and show an age-dependent post-hypoxic response. Moreover, aging caused either no change (GST, GR and CAT) or an increase (Se-GPX, Cu/Zn-SOD, Mn-SOD) in the basal activity of the enzymes analysed. Only Se-independent GPX activity decreases. However, we detected an age-dependent response of SODs to the hypoxic injury. The early and sustained Cu/Zn-SOD activity rise in adult animals became late and weak in aged animals. Meanwhile, aging slowed the Mn-SOD post-hypoxic response although this activity was consistently higher in aged rats. Aging eliminated the post-hypoxic CAT response, but, perhaps offset by increased GPX activity, did not affect the GST response and slightly reduced post-hypoxic GR activity. In conclusion, aging rise basal ROS production, does not diminish or even increase the antioxidative-enzyme activity, and may slow but does not usually eliminate the enzymatic antioxidant response to the increased post-hypoxic ROS generation.
Martínez-Romero
R
R
Department of Experimental Biology, University of Jaén, Paraje Las Lagunillas s/n, 23071-Jaén, Spain.
Cañuelo
A
A
Martínez-Lara
E
E
Hernández
R
R
Del Moral
M L
ML
Pedrosa
J A
JA
Peinado
M A
MA
Siles
E
E
D000375:Aging / Q000502:physiology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002540:Cerebral Cortex / Q000201:enzymology*; D002534:Hypoxia, Brain / Q000201:enzymology / Q000503:physiopathology*; D015227:Lipid Peroxidation; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase