title: Influence of estradiol administration on estrogen receptors of nasal mucosa: an experimental study on guinea pigs.
abstract: BACKGROUND
  Some clinical trials revealed a correlation between increased serum estrogen and nasal symptoms or inflammatory changes in nasal mucosa. Estrogen receptors tend to be controlled by a negative feedback, to avoid a deleterious stimulus over several body functions while in hyperestrogenic periods. This study proposes a hypothesis where mechanisms regulating expression of estradiol receptors in nasal mucosa are absent in some patients, and their concentration remains steady even in periods of high serum hormonal concentration, potentially leading to local estrogenic symptoms in nasal mucosa.
  
  
  METHODS
  This was an experimental prospective study.
  
  
  OBJECTIVE
  To determine whether estrogen levels induce the reduction of the number of estrogen receptors in the nasal mucosa.
  
  
  METHODS
  In the present study, 30 adult male guinea pigs were subjected to a biopsy of the middle nasal turbinate and received 0.5 mL of estradiol cypionate intraperitoneally for 30 consecutive days. Afterwards, samples from contralateral middle turbinate were obtained. Immunohistochemical analysis of estrogen receptors were performed pre- and post-treatment.
  
  
  RESULTS
  The post-treatment group showed reduction of receptor expression when compared to the pre-treatment group. (p = 5.2726-5).
  
  
  CONCLUSIONS
  A reduction in the expression of the nasal estrogen receptor was observed after 30 days of estradiol administration.
authors.forename: Henrique Olival
authors.initials: HO
authors.lastname: Costa
authors.forename: Ney Penteado de
authors.initials: NP
authors.lastname: Castro Neto
authors.forename: Lia Mara
authors.initials: LM
authors.lastname: Rossi
authors.forename: Ieda
authors.initials: I
authors.lastname: Millas
authors.forename: Flavia
authors.initials: F
authors.lastname: Coelho
authors.forename: Leonardo da
authors.initials: Ld
authors.lastname: Silva
mesh_terms: D000818:Animals; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008297:Male; D009297:Nasal Mucosa / Q000378:metabolism*; D011446:Prospective Studies; D011960:Receptors, Estrogen / Q000378:metabolism*; D013997:Time Factors
chemical_list: D011960:Receptors, Estrogen; D004958:Estradiol; C007630:estradiol 17 beta-cypionate