Comparative Study on the Estimation of Estrous Cycle in Mice by Visual and Vaginal Lavage Method

Abstract

Introduction: Evaluation of estrous cycle in laboratory animals can be a useful measure of the integrity of hypothalamic-pituitaryovarian reproductive axis. Assessment of vaginal cytology is crucial to assess the milieu and compare the endocrine status of animals among the experimental groups. Aim: The present study was attempted to compare the estimation of estrous cycle by visual method and non invasive vaginal lavage method. Materials and Methods: Sixty healthy female swiss albino mice were used for the present study. The appearance of the vagina with respect to the opening of vagina, vaginal swellings were observed. Non-invasive method was used in vaginal lavage method in which nucleated epithelial cells, cornified squamous epithelial cells and leucocytes present in vaginal smears were used to identify the estrous stages. Results: The estimation of estrous cycle by visual method coincides with the vaginal lavage method. In Vaginal lavage method, the accurate proportion of cells and the transition phases can be evaluated. Conclusion: The non-invasive method reduces the risk of pseudo -pregnancy and mechanical trauma. Though, visual method is quick and reliable, for accurate estimation of the stage of the estrous, non-invasive vaginal lavage method is ideal.

Keywords

• laboratory animals
• reproductive cycle
• vaginal cell morphology
• vaginal smears