title: The effects of raloxifene treatment on oxidative status in brain tissues and learning process of ovariectomized rats.
abstract: BACKGROUND
  The effects of estrogene on central nervous system are still controversial.
  
  
  OBJECTIVE
  We aimed to investigate the effects of raloxifene on the antioxidant enzyme [superoxide dismutase (SOD) and catalase (CAT)] activities and malondialdehyde (MDA) levels in brain homogenates of ovariectomized female rats and its effect on cognitive process of learning.
  
  
  METHODS
  Female Sprague Dawley rats (n=24) were divided into three groups. Three weeks after ovariectomy; nonovariectomized group (control group) (n=8) was given physiological saline (SP) as placebo. First ovariectomized group (n=8) received raloxifene 1mg/kg dissolved in a 1% solution of carboxymethylcellulose (CMC) subcutaneusly (sc) and second group of ovariectomized rats were given 1 % CMC 1mg/kg (sc) every day for 14 days. Learning behaviors of rats were evaluated in active avoidence cage with using sound and electrical stimulation. The levels of oxidative stress (MDA) and antioxidant enzymes (SOD, CAT) in different regions of the brain homogenates were compared between three groups of decapitated rats.
  
  
  RESULTS
  Raloxifene had a significant attenuating effect on the levels of MDA in brain tissues suggesting raloxifene's effect against lipid peroxidation at the end of training days. With the comparison of brain regions, cortex showed the highest average activity of SOD and CAT and cerebellum had the lowest average levels for both. Its effects on learning and cognitive process with active avoidence task were considered insignificant.
  
  
  CONCLUSIONS
  Raloxifene treatment may have preventive effects for the brain against oxidative stress and lipid peroxidation in rats.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey.
authors.forename: Süreyya
authors.initials: S
authors.lastname: Osmanova
authors.affiliation: Department of Biochemistry, Ege University, Faculty of Medicine, Bornova, Izmir, Turkey.
authors.forename: Ebru
authors.initials: E
authors.lastname: Sezer
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey.
authors.forename: Volkan
authors.initials: V
authors.lastname: Turan
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Zeybek
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Ege University, Bornova, Izmir, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Cosan Terek
authors.affiliation: Department of Physiology, Ege University, Faculty of Medicine, Bornova, Izmir, Turkey.
authors.forename: Lutfiye
authors.initials: L
authors.lastname: Kanıt
keywords: Active avoidence task; Cognitive process; Oxidative stress; Raloxifene