Unopposed Exogenous Estrogen Administration And its Effect on The Histomorphology of Endometrium in Swiss Albino Mice

Introduction: The morphology of endometrium undergoes changes in response to the sex hormones periodically. Estrogen predominantly causes mitotic activity and increases the proliferation of endometrium and progesterone antagonizes the activity of estrogen. However, factors which increase the circulating levels of estrogens such as exogenous intake of hormonal pills or endogenous increase of estrogens in response to obesity, early menarche and late menopause, chronic anovulatory cycles in PCOS can trigger proliferative lesions in the endometrium due to lack of progesterone. In the present study an attempt has been made to study the effect of unopposed estrogen administration through oral route in the histomorphology of endometrium in swiss albino mice. Material and Methods: In the present cross sectional study 24 healthy female swiss albino mice were randomly grouped into 2 groups. Group I is the control group (6 animals) and Group II (18 animals) is the experimental group for which 17 β – Estradiol had been administrated perorally for the period of 12 weeks. The animals were given normal pellet diet and water ad libitum. Result: In the present study, the endometrium showed normal morphology in the control group. Hormone treated group animals exhibited complex hyperplasia with nuclear atypia and increase in the glands stroma ratio. Conclusion: The prolonged period of increased levels of estrogen unopposed reciprocally by progesterone causes persistent morphological changes in the endometrium leading to neoplastic changes.