ENTACTIN ULTRASTRUCTURAL IMMUNOLOCALIZATION IN THE BASAL LAMINAE OF MOUSE SEMINIFEROUS TUBULES AND WITH ONLY SUBTLE CHANGES FOLLOWING HYPOPHYSECTOMY

While entactin has been recently reported in the mouse seminiferous tu bule lamina propria at the light microscope level, the purpose of this paper was twofold: 1) to determine the ultrastructural localization o f entactin with the two basal laminae that form the lamina propria of the mouse, and 2) to determine if immunoreactive entactin changes foll owing hypophysectomy. The localization of entactin was demonstrated by three different means: 1) immunofluorescent localization in semi-thin cryosections of the testis, 2) immunoperoxidase staining in a prepara tion of isolated lamina propria, and 3) immuno-gold staining in ultra- thin sections of testis. These techniques all demonstrated that immuno reactive entactin is present in both the inner and outer basal laminae of the mouse seminiferous tubules and is co-localized with laminin. T hese results are consistent with previous work that demonstrated entac tin is synthesized and secreted by both Sertoli and peritubular myoid cells. Because both Sertoli cells and peritubular myoid cells are andr ogen-responsive cells, we wanted to determine if hypophysectomy alters the testicular distribution of entactin. Changes in immunoreactive en tactin and laminin in the basal laminae were observed in semi-thin cry osections of the testes from hypophysectomized mice up to 6 weeks afte r surgery. The results demonstrated that during this time period, whil e most of the spermatogenic cells degenerated, the intensity of immuno reactive entactin and laminin remained nearly unchanged, as the semini ferous tubule basal laminae took on an increasingly wavy apparence. Th is suggests that the relative concentration of entactin and laminin in the basal lamina is stable, and not dependant on the presence of norm al spermatogenesis and pituitary hormones.