title: The effects of estrogen and raloxifene treatment on the antioxidant enzymes and nitrite-nitrate levels in brain cortex of ovariectomized rats.
abstract: Number of studies indicate that the female gonadal hormone estrogen protects women against several neurodegenerative diseases and cerebral ischemia via various mechanisms. The possible protective effects of estrogen are mediated mainly by three ways; the activation of steroid receptors and/or modulation of a neurotransmitter and/or direct antioxidative action. Therefore we aimed to investigate the effects of estradiol and raloxifene on levels of nitric oxide (NO) and antioxidant enzymes in brain cortex of ovariectomized female rats. Ten Sprague-Dawley rats were used as naive controls while 32 rats were ovariectomized at 120-140 days of age. Twelve weeks after ovariectomy: (1). Ovariectomized Placebo group (n=11), was given physiologic saline. (2). Estrogen group (n=10) was given Ethynyl estradiol, 0.1 mg/kg sc. (3). Raloxifene group (n=10) was given raloxifene, 1 mg/kg sc. At the end of the treatment period (8 weeks), rats were decapitated and cortex samples were dissected. Results showed that ovariectomy caused a decrease in total nitrite-nitrate levels. The NO levels of both the estrogen and the raloxifene group were higher than the placebo group. Catalase activities did not show any significant difference between the groups, while superoxide dismutase (SOD) activities were elevated via ovariectomy. Estradiol and Raloxifene treatment had no statistically significant effect on SOD activity.
authors.affiliation: Department of Endocrinology, Adnan Menderes University Faculty of Medicine, Biyokimya Anabilim Dali, Bornova-Izmir, Turkey.
authors.forename: Ayşin
authors.initials: A
authors.lastname: Oge
authors.forename: Ebru Demirel
authors.initials: ED
authors.lastname: Sezer
authors.forename: Mert
authors.initials: M
authors.lastname: Ozgönül
authors.forename: Firat
authors.initials: F
authors.lastname: Bayraktar
authors.forename: Eser Yildirim
authors.initials: EY
authors.lastname: Sözmen
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D005260:Female; D009566:Nitrates / Q000032:analysis; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000032:analysis; D010052:Ovariectomy; D020849:Raloxifene Hydrochloride / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020845:Selective Estrogen Receptor Modulators / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D009566:Nitrates; D009573:Nitrites; D020845:Selective Estrogen Receptor Modulators; D009569:Nitric Oxide; D004997:Ethinyl Estradiol; D020849:Raloxifene Hydrochloride; D002374:Catalase; D013482:Superoxide Dismutase