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

• Main Authors: Fatimeh Khodabandehloo, Mahmoud Hosseini, Ziba Rajaei, Mohammad Soukhtanloo, Esmaeil Farrokhi, Mohsen Rezaeipour
• Format: Article
• Language: English
• Published: Academia Brasileira de Neurologia (ABNEURO) 2013-05-01
• Series: Arquivos de Neuro-Psiquiatria
• Subjects: aprendizado; memória; ovariectomia; estradiol; Labirinto Aquático de Morris; estresse oxidativo
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X2013000500313&lng=en&tlng=en
• ISSN: 1678-4227

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.