The leucocyte‐like cells of the oviducts during the normal estrous cycle and their modification by progestin and estrogen treatment

During specific phases of the luteal stage of the estrous cycle, and during early pregnancy, or following progestational administration, there is a marked mobilization of lymphoblast‐like cells in the connective tissue of the plica. These cells readily penetrate the basment membrane, and assume an intercalary position in their migration between the epithelial cells to the lumen. Progestational treatment intensifies this migration during the luteal phase of the estrous cycle in the normal animal, or induces this migration in the oviducts of the ovariectomized animal. Estrogenic treatment alone, in the ovariectomized animal, will not maintain the migration of lymphoblast‐like cells in the connective tissue of the oviduct, nor their penetration between the epithelial cells and extrusion into the lumen of the tissue. Estrogenic treatment induces a marked modification of the lymphoblast‐like cells mobilized by progestational treatment, resulting in morphological reorganization and destruction of the cells in the oviductal tissues. The morphological reorganization of the cell is noted in eosinophilic granulation of the cytoplasm, followed by fragmentation of the nuclear chromatin within the cell. The eosinophilic granulation is lost, followed by dissolution of the nuclear and cytoplasmic membranes and scattering of the chromatin material into the tissue.