Uterine tubes from 21 crossbred heifers (Bos taurus taurus × Bos taurus indicus) at different phases of the natural estrus cycle (estrus, metaestrus and diestrus) or submitted to superovulation (superovulated estrus and metaestrus) were evaluated for the presence of intraepithelial cysts and for histochemical labelling of its contents. All studied animals had intraepithelial cysts mainly in the infundibular and ampullary regions. Such cysts were present regardless of the side of the uterine tube, ipsi- or contralateral to the active ovary (preovulatory follicle or corpus luteum) or of the cycle phase (estrogenic or progesteronic). Histochemical analysis revealed that neutral and acid mucins were the major substances found within the cysts. Sulphated mucins were present in low amounts and glycogen was absent. These results suggest that these cysts are probably formed by the fusion of intracytoplasmic lumina and/or ciliated vacuoles of the uterine tube epithelium.
uterine tube; intraepithelial cysts; bovine
