Oxidative stress in the hippocampus, anxiety-like behavior and decreased locomotory and exploratory activity of adult rats: effects of sub acute vitamin A supplementation at therapeutic doses.
Vitamin A participates in the maintenance of normal hippocampal function during embryonic and postnatal stages of the vertebrate life. Some works demonstrated that vitamin A metabolites impair learning and induce a depression-like behavior in mice, among other effects. Since vitamin A has prooxidant effects on other experimental models, we decided to investigate whether vitamin A can induce oxidative stress in the adult rat hippocampus. We analyzed the sub acute effects of therapeutic (1000 and 2500 I.U./kg) or excessive (4500 and 9000 I.U./kg) vitamin A doses on the hippocampal redox state, as well as on levels of anxiety, and locomotory and exploratory activity. Vitamin A supplementation induced lipid peroxidation, protein carbonylation, and oxidation of the protein thiol content in the rat hippocampus in all periods analyzed. Increased superoxide dismutase (SOD) activity and decreased catalase (CAT) activity were also observed, which gives rise to an imbalance in the principal cellular enzymatic antioxidant system. Then, our results show, for the first time, that vitamin A induced oxidative stress in the adult rat hippocampus, is anxiogenic, and decreases locomotion in and exploration of an open field.
de Oliveira
Marcos Roberto
MR
Centro de Estudos em Estresse Oxidativo (Laboratory 32), Department of Biochemistry, ICBS, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil. mrobioq@yahoo.com.br
Silvestrin
Roberta Bristot
RB
Mello E Souza
Tadeu
T
Moreira
José Cláudio Fonseca
JC
D000375:Aging / Q000378:metabolism; D000818:Animals; D001007:Anxiety / Q000139:chemically induced*; D001522:Behavior, Animal / Q000187:drug effects*; D002374:Catalase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects*; D005979:Glutathione Peroxidase; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects*; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D050050:Protein Carbonylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014801:Vitamin A / Q000633:toxicity*; D014815:Vitamins / Q000633:toxicity*
D013438:Sulfhydryl Compounds; D014815:Vitamins; D014801:Vitamin A; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase