The reproductive-age rats uterine tubes epithelium morphological and functional changes at bilateral ovariectomy

Ovariectomy leads to hormonal dysfunction, which manifests itself at all levels of the structural organization of the female reproductive system, including the epithelial lining of the uterine tubes. The aim of this study was to investigate the morphological and functional characteristics of the epithelial lining of all sections of the uterine tubes in reproductive-aged rats with bilateral ovariectomy. Twenty-six-month-old female Wistar rats served as subjects for the morphological study. All animals were divided into two groups: 10 females in the control group and 10 females with ovariectomy. Ovariectomy was used as an experimental model to exclude the influence of ovarian hormones on the uterine tubes. The uterine tubes were fixed in 10% buffered formalin, then paraffin sections (4 μm thick) were cut and stained with hematoxylin and eosin. Cell counts were calculated based on at least 1000 cells per animal. Morphometric analysis of tissue components of the epithelial lining of the uterine tube mucosa was measured using the ImageJ software. Estrous cycle phase was determined by staining vaginal smears using the RAPIHEM protocol. Rats in the control and experimental groups were in the resting phase. Fisher's exact test was used to test for homogeneity of variances. Differences were considered statistically significant at a significance level of p < 0.05. After bilateral ovariectomy, the uterine tube epithelium undergoes significant restructuring in all sections, manifested by an increase in mucosal thickness and a transformation of the cellular composition. The greatest changes are observed in the ampullary and uterine sections of the uterine tubes. The ampullary section is characterized by a 2.6-fold decrease in intercalated cells and a 3.5-fold increase in secretory cells. For the uterine section, the percentage of secretory cells increases by 2.0. The ciliary beat frequency of the uterine tube epithelium decreased by 40% in all regions compared to the control group. These changes are a potential risk factor for uterine tube dysfunction.