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.

Anti-Menopausal Effects of Cornus officinalis and Ribes fasciculatum Extract In Vitro and In Vivo

“…ERα in the uterus plays an especially critical role in mediating estrogen action. Accordingly, a study showed that estrogen deficiency induced atrophy in the uterus of OVX rats [32]. In the present study, the CO + RF extract increased the mRNA expression of mouse ERα (ESR1) in the murine uterus and estradiol secretion in ADD-induced COV434 granulosa cells.…”

“…Since uterine weight and morphology is regulated by estrogen concentrations [32], we investigated the effects of CO + RF mixtures of uterine weight in the OVX mice model. OVX mice resulted in reduced uterine weight and uterine atrophy, compared to the sham group.…”

Tibial nerve stimulation increases vaginal blood perfusion and bone mineral density and yield load in ovariectomized rat menopause model

“…Eight weeks after OVX, VBF ceased to be affected by PTNS, however. The OVX surgery causes vaginal atrophy [23] and decreases vaginal innervation [24] in both rats and humans [25]. Over time, this could decrease the target organ’s ability to be stimulated or provide an adequate response to PTNS.…”

Genistein and Sex Hormone Supplementation Modulated Hepatic PPARα, δ, and γ Subtypes and STAT1 Expressions in a NASH Rat Model with Bilateral Orchidectomy

“…Testosterone enanthate dosage at 50 mg/kg BW (Bayer Pharma AG, BER, Germany) was derived from our pilot study. Estradiol valerate dosage at 1.6 mg/kg BW was derived from Li T and colleagues [ 19 ], having been proven to be effective in reducing obesity and vulvovaginal atrophy in ovariectomized rats. Additionally, genistein dosage at 16 mg/kg BW was based on our previous publications, which demonstrated its efficacy in improving NASH induced via OVX + HFHF diet in female rats [ 14 , 20 ].…”