Influence of estradiol administration on estrogen receptors of nasal mucosa: an experimental study on guinea pigs

Introduction: 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. Study design: This was an experimental prospective study. Aim: 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). Conclusion: A reduction in the expression of the nasal estrogen receptor was observed after 30 days of estradiol administration. (C) 2014 Associacao Brasileira de Otorrinolaringologia e Cirurgia Cervico-Facial. Published by Elsevier Editora Ltda. All rights reserved.