Increased cerebral oxidative damage and decreased antioxidant defenses in ovariectomized and sham-operated rats supplemented with vitamin A.
Previous studies have linked oxidative stress with aging and aging-related processes, including menopause. Abnormalities in the redox state similar to those observed in menopausal women can be modeled experimentally with rat ovariectomy. The aim of the present study was to investigate the effects of vitamin A (retinol palmitate) supplementation (500 or 1,500 IU kg(-1) day(-1) for 30 days) on behavioral parameters and brain redox profile in ovariectomized (OVX) and sham-operated rats. Ovariectomy caused pronounced uterine atrophy and decreased locomotor/exploratory activity. Moreover, we found increased hypothalamic and frontal cortex superoxide dismutase/catalase (SOD/CAT) ratio and decreased hippocampal thiol content, accompanied by increased frontal cortex lipid oxidative damage (TBARS) in OVX rats. Vitamin A at 1,500 IUkg(-1) day(-1) decreased exploratory behavior and decreased total hippocampal thiol content in sham-operated rats, increased hippocampal SOD/CAT ratio and decreased total antioxidant potential in the hippocampus of both sham and OVX groups, and increased cortical TBARS levels in OVX rats. Thus, vitamin A may induce a pro-oxidant state in discrete brain regions of sham-operated and OVX rats. These results suggest some caution regarding the use of high doses of vitamin A supplementation during menopause.
Center of Oxidative Stress Research, Professor Tuiskon Dick Department of Biochemistry, Institute of Health Basic Sciences, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil. guibehr@gmail.com
Guilherme Antonio
GA
Behr
Carlos Eduardo
CE
Schnorr
André
A
Simões-Pires
Leonardo Lisbôa
LL
da Motta
Benicio N
BN
Frey
José Cláudio Fonseca
JC
Moreira
D000818:Animals; D000975:Antioxidants / Q000009:adverse effects*; D002374:Catalase / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D019587:Dietary Supplements / Q000009:adverse effects*; D005106:Exploratory Behavior / Q000187:drug effects; D005260:Female; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008593:Menopause / Q000378:metabolism; D023421:Models, Animal; D009043:Motor Activity / Q000187:drug effects; D010052:Ovariectomy; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014801:Vitamin A / Q000009:adverse effects*
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D014801:Vitamin A; D002374:Catalase; D013482:Superoxide Dismutase