Characterization of the citológical profile of the vaginal mucous during the estral cycle in the Santa Inês sheep

Abstract

The objective of the work was to characterize the cycle of the vaginal epithelium of sheep of the Santa Inês breed, through a cytological study. Vaginal mucosal samples were taken from 10 sexually mature ewes, from the first day of estrus and for 18 days. The samples were stained with Papanicolaou and observed under an optical microscope. Parabasal, de epintermediate, superficial intermediate, and superficial cells were recognized. The parabasal cells presented a rounded shape, little cytoplasm, and a large nucleus, they were scarce. The deep intermediate ones with rounded edges, more abundant cytoplasm, and smaller nuclei. They were observed in greater quantity than the parabasal ones. The superficial intermediate ones were the most abundant through out the study and the one swith the largest diameter. They presented a polygonal shape and a smaller nucleus. The identification of two types of intermediate cells coincides with works on dogs, cows, and alpacas, while other works describe a single type. Superficial cells were divided into two subtypes, A, with a polygonal shape and piknotic nucleus, and B, with a smaller and intensely acidophilic cytoplasm and pyknotic nucleus. The latter has not been found so far in other works with sheep. Changes in cell types did not accurately reflect the phase of the estrous cycle.