The histological effects of vitamin A supplement on the vaginal epithelial cells during estrus and luteal phases in Awassi sheep

This study was carried out on the vaginal epithelium of eight Awassi ewes during estrus and luteal phases in order to evaluate the histological effect of vitamin A on the vaginal epithelium, vaginal smears were taken and stained by methylene blue. Light microscope was used in examination of slides. The present result revealed that vitamin A stimulated the process of keratinization which in turn raised the immune response of the vagina. The process of keratinization formed a sheet of strongly attached polygonal cells which lines the vagina. Moreover, the most striking conclusion from this study was the indication to the period of arrival of the neutrophils from the blood to the vaginal epithelium which lasts more than six hours. These observations indicate the importance of vitamin A in proliferation, keratinization and increase cellular immunity of the vagina.