title: The possible role of estrogen and selective estrogen receptor modulators in a rat model of Parkinson's disease.
abstract: OBJECTIVE
  The aim of the present study was to assess and compare the effect of 17β-estradiol and two different selective estrogen receptor modulators (SERMs), tamoxifen and raloxifene, as well as a selective estrogen receptor alpha agonist, propyl-pyrazole-triol (PPT) and a selective estrogen receptor beta agonist, diarylpropionitrile (DPN), on behavioral and biochemical alterations in 6-hydroxydopamine (6-OHDA)-induced nigral dopaminergic cell death in rats.
  
  
  METHODS
  80 female Wister rats were used. Animals were divided into eight equal groups: Group I; Sham operated, Group II; subjected to ovariectomy (OVX), Group III; OVX rats received striatal injection of 6-OHDA, Groups IV-VIII; OVX rats received striatal injection of 6-OHDA and were injected daily with 17β-estradiol, tamoxifen, raloxifene, PPT and DPN respectively for 5days before 6-OHDA and continued for further 2weeks.
  
  
  RESULTS
  Results showed that striatal injection of 6-OHDA produced significant behavioral alteration suggestive of PD, together with significant decrease in striatal dopamine, homovanillic acid (HVA) and 3,4-dihydroxyphenyl acetic acid (DOPAC) concentrations. 6-OHDA-induced nigral dopaminergic cell death was characterized by oxidative stress, evidenced by significant decrease in striatal glutathione peroxidase activity, as well as apoptosis, evidenced by significant increase in nigral caspase-3 activity. Treatment with 17β-estradiol, raloxifene, PPT, but neither tamoxifen nor DPN, resulted in significant amelioration of the behavioral and biochemical alterations induced by 6-OHDA.
  
  
  CONCLUSIONS
  These findings suggest that estrogen and some SERMs having estrogenic agonist activity in the brain, like raloxifene, might exert beneficial effect in PD.
authors.affiliation: Clinical Pharmacology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt. mnhbaraka@yahoo.com
authors.forename: Azza M
authors.initials: AM
authors.lastname: Baraka
authors.forename: Aida A
authors.initials: AA
authors.lastname: Korish
authors.forename: Gehan A
authors.initials: GA
authors.lastname: Soliman
authors.forename: Hanan
authors.initials: H
authors.lastname: Kamal
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004958:Estradiol / Q000494:pharmacology / Q000627:therapeutic use*; D047628:Estrogen Receptor alpha / Q000819:agonists / Q000502:physiology*; D047629:Estrogen Receptor beta / Q000819:agonists / Q000502:physiology*; D004967:Estrogens / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D010052:Ovariectomy; D010300:Parkinson Disease / Q000188:drug therapy / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D020845:Selective Estrogen Receptor Modulators / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D020845:Selective Estrogen Receptor Modulators; D004958:Estradiol