Authors: Adebayo Koyuum Akinloye, Bankole Olusiji Oke
Abstract: Anatomies of the cervices in African giant rat during oestrous cycle are described. Two cervices separated by a mid-saggital septum were observed. The cervical canal was straight and had 4 – 5 interlocking longitudinal mucosal folds. Cervical histology showed mucosa-submucosa, muscularis and serosa layers with fused muscular layers between the two cervices forming mid-septum. Cervical epithelium interspersed with tall mucoid cells, varied between stratified cuboidal and stratified columnar. Differential distribution of the mucous-secreting cells occurred during oestrous cycle. The luminal surface had blebs that were residual components of cervical plugs. At mid-metestrus and mid-diestrus, numerous lymphocytes were observed in the lamina propria and there was less mucous secretion. The cervical ultrastructures were variable during oestrous cycle. At mid-estrus, the interface of basal layer and lamina propria was folded with cytoplasmic extension of the basal cells in the underlying connective tissue. Minor intercellular spaces with projections of cell extensions were observed. Relatively straight basal lamina interfacing the basal layer and the underlying lamina propria showed hemidesmosomes with minor projections of cytoplasm. Indented nuclei containing condensed material were observed and intraepithelial lymphocytes commonly occurred in the basal cells. At mid-proestrus, dorsoventally flattened cells containing slightly indented, elongated nuclei with euchromatic and heterochromatic materials were observed. The findings of this study establish cyclic changes in the anatomy of cervices and suggest that perhaps ovulation takes place during late proestrus/early estrus in the female African giant rat.
Keywords: Cervix, Oestrous, Giant Rat, Ultrstructure, Histology