title: Increased blood oxidative stress in experimental menopause rat model: the effects of vitamin A low-dose supplementation upon antioxidant status in bilateral ovariectomized rats.
abstract: Menopause has been reported to be associated with increased oxidative stress and metabolic disorders among women worldwide. Disarrangements in the redox state similar to those observed in women during the decline of ovarian hormonal activity can be obtained experimentally through rat bilateral ovariectomy. The search for alternative treatments to improve life quality in postmenopausal woman is really important. The aim of this study was to evaluate biochemical and oxidative stress parameters that distinguish sham-operated female rats from Wistar rats bilaterally ovariectomized (OVX). Additionally, we have also investigated the effects of retinol palmitate (a vitamin A supplement) low-dose supplementation (500 or 1500 IU/kg/day, during 30 days) upon blood and plasma antioxidant status in OVX rats. Ovariectomy caused an increase in body weight gain, pronounced uterine atrophy, decreased plasma triglycerides and increased total cholesterol levels, and reduced acid uric content. Moreover, we found increased blood peroxidase activities (catalase and glutathione peroxidase), decreased plasma non-enzymatic antioxidant defenses total reactive antioxidant potential and total antioxidant reactivity, decreased protein and non-protein SH levels, accompanied by increased protein oxidative damage (carbonyl). In addition, vitamin A low-dose supplementation was capable to ameliorate antioxidant status in OVX rats, restoring both enzymatic and non-enzymatic defenses, promoting reduction in plasma SH content, and decreasing protein oxidative damage levels. This is the first work in the literature showing that vitamin A at low dose may be beneficial in the treatment of menopause symptoms. Further studies will be made to better understand the effects of vitamin A supplementation in menopause rat model.
authors.affiliation: Center of Oxidative Stress Research, Professor Tuiskon Dick Department of Biochemistry, Institute of Health Basic Sciences, Federal University of Rio Grande do Sul, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil. guibehr@gmail.com
authors.forename: Guilherme Antônio
authors.initials: GA
authors.lastname: Behr
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Schnorr
authors.forename: José Cláudio Fonseca
authors.initials: JC
authors.lastname: Moreira
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D004195:Disease Models, Animal; D004224:Diterpenes; D004305:Dose-Response Relationship, Drug; D005260:Female; D008055:Lipids / Q000097:blood; D008593:Menopause; D010052:Ovariectomy; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D012172:Retinaldehyde / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000097:blood; D014599:Uterus / Q000187:drug effects / Q000473:pathology; D015430:Weight Gain / Q000187:drug effects
chemical_list: D000975:Antioxidants; D004224:Diterpenes; D008055:Lipids; D013438:Sulfhydryl Compounds; C033889:retinal palmitate; D012172:Retinaldehyde