Increased levels of superoxide in brains from old female rats.
Hypertension, aging and a range of neurodegenerative diseases are associated with increased oxidative damage. The present study examined whether superoxide (O2*-) levels in brain are increased during aging in female rats, and the role of superoxide dismutase (SOD) and oestrogen in regulating O2*- levels. Young adult (3 month) and old (11 month) female spontaneously hypertensive stroke prone rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY) were studied. O2*- levels were measured in brain homogenates by lucigenin chemiluminescence and SOD expression by Western blotting. Ageing significantly increased brain O2*- levels in WKY (cortex +216%, hippocampus +320%, striatum +225%) and to a greater extent in SHRSP (cortex +540%, hippocampus +580%, striatum +533%). Older SHRSP showed a decline in cortical Cu/Zn SOD expression compared to young adult SHRSP. Oestrogen did not attenuate O2*- levels. The results show a significant age-dependent increase in brain O2*- levels which is exaggerated in SHRSP. The excess cortical O2*- levels in the SHRSP may be associated with a down-regulation of Cu/Zn SOD but are not related to a decrease in oestrogen.
Antier
Daniel
D
Division of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, Scotland, UK.
Carswell
Hilary V O
HV
Brosnan
M Julia
MJ
Hamilton
Carlene A
CA
Macrae
I Mhairi
IM
Groves
S
S
Jardine
E
E
Reid
John L
JL
Dominiczak
Anna E
AE
D000375:Aging / Q000378:metabolism; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001921:Brain / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D005260:Female; D010052:Ovariectomy; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013482:Superoxide Dismutase / Q000378:metabolism* / Q000502:physiology; D013481:Superoxides / Q000378:metabolism*
D013481:Superoxides; D004958:Estradiol; D013482:Superoxide Dismutase