title: Differential Regulation of Morphology and Estrogen Receptor-Alpha Expression in the Vagina of Ovariectomized Adult Virgin Rats by Estrogen Replacement: A Histological Study.
abstract: Background. To determine the exact role of estrogen in vaginal tissue morphology and estrogen receptor-alpha (ERα) distribution in the vagina, which remains controversial. Methods. Sixty rats were randomly categorized: sham-operated (sham), ovariectomy (OVX), and four estradiol treatments (estradiol valerate at 0.4, 0.8, 1.6, and 3.2 mg/kg/day) for 2 weeks. Thereafter, vaginal samples were biopsied from the distal- and proximal-half portions. The percentage of ERα-immunoreactive cells and the ERα score were quantified using immunohistochemistry to assess changes in ERα expression and distribution. Results. OVX induced significant vaginal atrophy and organic index. Estrogen-replacement therapy (ERT) reversed vaginal atrophy. The vaginal distal-half areas showed lower ERα% than the proximal-half areas. The ERα% increased sharply 4 weeks after OVX, especially in the epithelial layer (P = 0.023). ERT elicited different degrees of reductions in tissues after the 2-week treatment, but the ERα% in only the epithelium recovered in parallel with that in the sham group (P = 0.001). The OVX group showed higher ERα histological scores than the sham group, and the distal-half area changed more evidently than the proximal-half area. ERα expression was nearly unchanged after ERT (P > 0.05). Conclusions. ERT is effective for treating obesity and vulvovaginal atrophy caused by hypoestrogenism and advancing age in menopausal women but cannot recover the distribution and expression of ERα.
authors.affiliation: Department of Obstetrics and Gynecology, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.affiliation: Animal Center Laboratory, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Pathology, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Nuclear Medicine, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yan
authors.affiliation: Department of Obstetrics and Gynecology, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Huo
authors.affiliation: Animal Center Laboratory, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Yongyan
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Obstetrics and Gynecology, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Pathology, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Obstetrics and Gynecology, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Miao
authors.identifier: 0000-0002-6527-1405
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics and Gynecology, Peking University First Hospital, 8 Xishiku Street, Beijing 100034, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Liu