Histological Changes of the Ampullary Epithelium of Cyclic Albino Rat Oviduct: Light and Ultrastructure Examination

The mammalian oviduct especially the ampulla part plays an essential role in female reproduction as fertilization, oocyte maturation and early embryonic development. The present study was focused on the microscopic changes of the rat ampulla epithelium during the oestrous cycle and correlates the findings with their possible functions. Twenty five rats of regular 5 day oestrous cycles were used in our study. They were divided into 5 groups; five rats in each phase of estrous cycle (early proestrus, late proestrus, estrus, metestrus and diestrus). They were sacrificed and the ampullae were excised, fixed and processed to be examined by light and electron microscopy. Marked changes in both relative number and the structure of ciliated and secretory cells throughout the estrous cycle were seen. Ciliated cells were increased in the relative number at the early proestrus till became the predominant cell type at the late proestrus then decreased at the estrus phase accompanied by deciliation. The secretory cells increased in the relative number and prevailed at the metestrus with increasing in the secretory activity. They became rare at the diestrus, a day on which the first sign of neociliogenesis was recorded. Intra epithelial glands were firstly appeared at the estrus phase which increased in number and size at the metestrus. The secretory material is showed PAS positive reaction in the estrus and the metestrus.