title: Brain tissue oxidative damage as a possible mechanism for the deleterious effect of a chronic high dose of estradiol on learning and memory in ovariectomized rats.
abstract: In addition to antioxidative effects, estrogens also exert pro-oxidative actions. The effect of chronic administration of a high dose of estradiol valerate on Morris water maze tasks and brain tissues oxidative damage was investigated. The Sham-Est and OVX-Est groups were treated with estradiol valerate (4 mg/kg) for 12 weeks. Escape latency and traveled path in the Sham-Est and OVX-Est groups were significantly higher than in the Sham and OVX groups (p<0.01 and p<0.001). In the probe trial, the animals of the Sham-Est and OVX-Est groups spent lower time in Q1 compared to Sham and OVX groups (p<0.05 and p<0.001). In Sham-Est and OVX-Est groups, the brain tissue total thiol concentration was significantly lower, and malondialdehyde (MDA) concentrations were higher than in the Sham and OVX groups (p<0.05 and p<0.001). It is concluded that administration of high exogenous levels of estradiol impairs performance and enhances oxidative stress.
authors.affiliation: Department of Physiology, School of Medicine, AJA University of Medical Sciences, Tehran, Iran.
authors.forename: Fatimeh
authors.initials: F
authors.lastname: Khodabandehloo
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Hosseini
authors.forename: Ziba
authors.initials: Z
authors.lastname: Rajaei
authors.forename: Mohammad
authors.initials: M
authors.lastname: Soukhtanloo
authors.forename: Esmaeil
authors.initials: E
authors.lastname: Farrokhi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Rezaeipour
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D004967:Estrogens / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D008315:Malondialdehyde / Q000032:analysis; D018782:Maze Learning / Q000187:drug effects*; D008568:Memory / Q000187:drug effects*; D010052:Ovariectomy; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D004967:Estrogens; D004958:Estradiol; D008315:Malondialdehyde