The changes in morphology and morphometrical indices of endometrium of ovariectomized mice in response to exogenous ovarian hormones

Background: The preparation of endometrium for embryo reception and implantation are controlled by ovarian hormones. These hormones have distinct cyclical changes during estrus cycle.
Objective: The aim of this study was to evaluate the changes in morphology and morphometrical indices of endometrium by daily injections of estrogen and progesterone in ovariectomized mouse.
Materials and Methods: In total 60 adult NMRI female mice were ovariectomized and after two weeks, they were randomly divided into five groups: control, sham group, estrogen treated mice (which received daily dosage of 0.5 ml/mouse of hormone for five days), progesterone treated mice (which received daily dosage of 0.2 ml/mouse of progesterone hormone for five days) and estrogen-progesterone treated mice (they received 0.5 ml/mouse estrogen on the first day and 0.2 ml/mouse progesterone injections from the second day to the fifth day of treatment). The mice were sacrificed in every day (n=5) up to five days after treatment and their uterine horns were obtained and processed for morphological and morphometrical studies.
Results: On the second day of treatment, the diameter of glands was observed to be more in the progesterone group (53.75±6.32μ) than this in the estrogen (45.13±7.78 μ) and estrogen-progesterone treated groups (48.17±13.58 μ). While, the number of glands (76.25±17.37) and thickness of endometrium (39.58±3.37 μ) were observed to be more in the estrogen treated group (p=0.01).
Conclusion: Progesterone had effect on the gland whereas estrogen caused increased in height of surface epithelium of endometrium. Overall, the day 2 after treatment (in all experimental groups) is suitable day for sampling for further studies.

Keywords
Endometrium, Exogenous ovarian hormones, Ovariectomized mice, Morphometry, Morphology.