SummaryHistological and electron microscopical examinations of the vaginal epithelium of the cowThe vaginal epithelium of the cow was not uniform. Its structure depended on the place from where a sample was taken, the hormonal status of the animal, and other (individual) factors. From each of 23 cows 11 tissue samples were taken at equal distances from the entire length of the vagina. Some cows had low blood hormone values, others were under gestagen dominance and still others under the influence of estradiol. In cows with low blood hormone values, tissue samples 1 and 2 (E 1 and E 2), which corresponded to the fornix and its junction with the vagina proper, showed an epithelium of one or two layers of cylindrical cells. Tissue samples E 3 to E 5 (cranial half of the vagina) were dominated by an epithelium consisting of three layers, i. e. two layers of basal cells and one variably shaped layer of apical cells. In E 6 to E 10 (caudal half) the height of the epithelium increased from three to about ten cell layers; a stratum intermedium of variable thickness could be discerned. Tissue sample Ell (vestibule) had a non‐cornified squamous epithelium of multiple layers. Cows under the influence of gestagen had an epithelium which in principle was similar to the above findings. In cows under the influence of estradiol, the rate of cell proliferation was increased, the epithelium was thicker throughout, showed an active tendency of desquamation, and that in the vestibule had the potential to become cornified. Free cells (lymphocytes and plasma cells) were found in all areas; they were more numerous in animals under the influence of gestagen. In animals under the influence of estradiol also neutrophils were encountered.PAS‐positive mucosubstances containing acid groups were found in the apical cells of the cranial end of the vagina. These substances could be responsible for a typical reaction (Kuppenreaktion) in the epithelial type that featured a stratum intermedium. Apart from folds the vaginal epithelium contained genuine intraepithelial and subepithelial glands.
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