Tissue concentrations of mast cells and lymphocytes of the bovine uterine tube (oviduct) during the estrous cycle.

Estrous cycle fluctuations in the mast cell and lymphocyte counts (per mm2 of tissue) of the ampulla and isthmus of the bovine uterine tube (oviduct) were determined. Four random sections of each region of the uterine tube were prepared at 2 micron thickness and stained with toluidine blue. The mast cell count of the isthmus was found to be significantly higher (P less than 0.01) than the mast cell count of the ampulla for all stages of the estrous cycle. A significant increase (P less than 0.01) in the mast cell value of the isthmus occurred during metestrus, diestrus, and proestrus. In the ampulla, metestrous and diestrous mast cells numbers were significantly higher (P less than 0.05) than mast cell numbers during estrus. The lymphocyte numbers remained relatively constant in both the ampulla and the isthmus except during diestrus, when ampullary lymphocyte numbers increased significantly (P less than 0.05). Lymphocytes were observed to migrate through the uterine tube epithelium and mast cells were observed only in the lamina propria.