title: Estrogen therapy for experimental intracerebral hemorrhage in rats.
abstract: OBJECTIVE
  The aims of this study were to determine the following: whether there are sex differences in intracerebral hemorrhage (ICH) induced brain injury in rats, whether delayed administration of 17beta-estradiol can reduce ICH-induced brain damage, and whether these effects are estrogen receptor (ER)-dependent.
  
  
  METHODS
  Male and female Sprague-Dawley rats received an infusion of 100 microl autologous whole blood into the right basal ganglia. Twenty-four hours later the rats were killed. The effects of 17beta-estradiol on ICH-induced brain injury were examined by measuring brain edema and neurological deficits. Both ER-alpha and hemeoxygenase (HO)-1 were investigated through Western blot and immunohistochemical analysis. Brain edema was significantly less severe in female compared with that in male rats. The ER antagonist ICI 182,780 exacerbated ICH-induced brain edema in female but not in male rats, indicating that ER-alpha activation during ICH is protective in female rats. Administration of exogenous 17beta-estradiol in male, but not in female, rats significantly attenuated brain edema, neurological deficits, and ICH-induced changes in HO-1 when given 2 hours after hemorrhage. The effects of exogenous 17beta-estradiol occurred through an ER-independent mechanism.
  
  
  CONCLUSIONS
  Results in this study indicate that 17beta-estradiol could be a potential therapeutic agent for ICH.
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan 48109-0532, USA.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Nakamura
authors.forename: Ya
authors.initials: Y
authors.lastname: Hua
authors.forename: Richard F
authors.initials: RF
authors.lastname: Keep
authors.forename: Jung-Weon
authors.initials: JW
authors.lastname: Park
authors.forename: Guohua
authors.initials: G
authors.lastname: Xi
authors.forename: Julian T
authors.initials: JT
authors.lastname: Hoff
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D001929:Brain Edema / Q000209:etiology* / Q000378:metabolism / Q000517:prevention & control*; D002543:Cerebral Hemorrhage / Q000150:complications*; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D004958:Estradiol / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000494:pharmacology; D004965:Estrogen Antagonists / Q000494:pharmacology; D005260:Female; D000077267:Fulvestrant; D006419:Heme Oxygenase (Decyclizing) / Q000187:drug effects / Q000378:metabolism; D051547:Heme Oxygenase-1; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011960:Receptors, Estrogen / Q000187:drug effects; D012737:Sex Factors
chemical_list: D004965:Estrogen Antagonists; D011960:Receptors, Estrogen; D000077267:Fulvestrant; D004958:Estradiol; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1