title: Beta-estradiol reduces lipid peroxidation and depth of injury in cold-induced brain injury model.
abstract: Estrogen has neuroprotective effects in neurodegenerative disorders and models of neuronal damage. The effectiveness of estradiol (EST) (1 mg/kg and 10 mg/kg doses) in cold-induced brain injury (CIB) model was evaluated and compared with standard dexamethasone treatment. Forty-eight male Wistar rats (250-300 g) were randomly divided into 6 groups: sham operated, CIB + no treatment, CIB + 1 mg/kg dexamethasone, CIB + 1 mg/kg EST, CIB + 10 mg/kg EST, CIB + vehicle (ethanol). Rats were placed on stereotaxic frame and a craniotomy of 5 mm diameter was performed on the parietal lob under general anesthesia (ketamine+xylazine). A metal probe of 5 mm diameter was cooled (2 min) in liquid nitrogen (-190 degrees C) and was applied on the craniotomy area for 3 min. The treatment was started immediately after the CIB. Twenty-four hours later the whole brain was isolated and study parameters were assessed. The parameters were tissue wet/dry weight ratio, lipid peroxidation, and histopathological examination of the depth of injury. Both 1 mg/kg dexamethasone and 1mg/kg EST treatment significantly reduced all the measured injury parameters, whereas 10 mg/kg EST had no effect on any of the parameters. This study shows that EST at lower concentrations is beneficial in this model of cold-induced brain injury. However, the effect of EST is dual and higher concentrations, in contrast, do not affect or even may be detrimental in brain injury.
authors.affiliation: Ankara Numune Training and Research Hospital, 2nd Clinic of Neurosurgery, Ankara, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Seçer
authors.forename: Incilay
authors.initials: I
authors.lastname: Sinici
authors.forename: Aylin
authors.initials: A
authors.lastname: Heper
authors.forename: M Fikret
authors.initials: MF
authors.lastname: Ergüngör
authors.forename: Hakan
authors.initials: H
authors.lastname: Ergün
mesh_terms: D000818:Animals; D001834:Body Water / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D001930:Brain Injuries / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003080:Cold Temperature; D003907:Dexamethasone / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D004967:Estrogens / Q000008:administration & dosage / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004967:Estrogens; D018696:Neuroprotective Agents; D004958:Estradiol; D003907:Dexamethasone