The Ultrastructure of the Rete Testis and Its Permeability Barrier Before and After Efferent Ductule Ligation

The rete testis of the bull, ram, boar, goat, rabbit, cat and rat was lined with a simple epithelium that varied in height from flat to tall columnar. The ultrastructure of the rete epithelium did not indicate protein secretion. The presence of many microvesicles in the rete epithelium suggested that these cells might be involved in transport of substances across the epithelium. A few spermatozoa were observed within the cytoplasm of the apical part of the cells. Neighbouring cells were attached together by desmosomes and adluminal tight junctions. Intraepithelial lymphocytes were frequently observed between the rete cells near the basal lamina. The adluminal tight junctions between the rete cells efficiently blocked lanthanum from reaching the lumina of the rete channels. Efferent ductule ligation had no harmful effect upon the permeability of the blood-testis barrier in the rete testis as judged by lanthanum technique. A few myoid cells were found in the connective tissue of the mediastinum near the rete channels.