Epithelial Phagocytosis of Spermatozoa and Latex Beads in the Terminal Segment of the Seminiferous Tubule in the Rat

Phagocytosis of spermatozoa and latex beads by the modified Sertoli cells, which are epithelial cells lining the terminal segment of the seminiferous tubule and forming a plug-like structure in the terminal region of the segment, was observed in the rat with TEM. Degenerated spermatozoa could occasionally be found in the cytoplasm of the modified Sertoli cells in the terminal plug. At the tip of the plug in some terminal segments, luminal macrophages loaded with a cluster of phagocytosed spermatozoa were also observed. Latex beads injected into the lumen of the rete testis were taken up by the modified Sertoli cells through pseudopodium formation and were finally concentrated in the lysosomal bodies of these cells. In this account, the phagocytic ability of the modified Sertoli cells was established and the significance was briefly discussed.