Fine structure of Sertoli cells in the rat testis after hypophysectomy, testosterone treatment and re-involution.

Using thin sections and freeze-etch replicas the fine structure of the Sertoli cells of the rat testis was investigated after hypophysectomy, testosterone treatment and re-involution. 41 days after hypophysectomy the Sertoli cells contain numerous dense bodies and remnants of degenerating spermatocytes and spermatids. The Sertoli cell junctions are most prominent. The membranes of neighbouring cells are folded into several layers. Freeze-fracture replicas reveal a normal arrangement of Sertoli cell tight junctions with linear array of membrane particles preferentially on the B-face and complementary grooves on the A-face. The geometric pattern of the ridges is varying with respect to the basal, intermediate and apical portions of the lateral Sertoli cell membranes. Since no major changes of the size, distribution and localization of the Sertoli cell junctions were observed in the different experimental groups these junctions, once formed, are inferred to be independent from hypophyseal hormones.