Endometrial specimens were obtained from normally cyclic buffalo at known stages of their estrous period to show precise characteristic changes.
with These tissues were embedded in paraffin, sectioned and stained hematoxylin and eosin. The following histological changes were observed: During estrous, the stroma was highly oedematous with highly congested blood capillaries and few migratory cells directed toward the lumen. The endometrial glands showed prominent and regularly distributed vacuolation. These vacuoles displace the nuclei upward to create a pattern of
pseudostratification. During met-estrous: The stroma was denser with a marked decrease in oedematous fluid and highly infiltrated lymphocyte and mast cells. Most of the vacuoles of the endometrial glands have discharged its secretion, and a homogenous acidophilic secretion reached its peak and accumulated in the lumen. During di-estrous: The stroma looked like a solid sheet of closely packed stromal cells. Some stromal cells showed signs of transformation into predecidual cells. The glandular epithelium showed an orderly row of nuclei with homogenous acidophilic cytoplasm above them. During pro-estrous, the stroma divided into outer condensed non functional layer and inner loosed layer with few migratory cells. The endometrial glands lined with inactive, low columnar darkly stained cells.