The present study examines events of the Sertoli cell iron delivery pathway following the secretion of diferric testicular transferrin (tTf) in to the adluminal compartment of the rat seminiferous epithelium. The unidirectional secretion of tTf by Sertoli cells was verified, in vivo, and it was shown that this protein is internalized by adluminal germ cells. It was further determined by Scatchard analysis that this internalization was mediated by high affinity transferrin binding sites on the surface of round spermatids, numbering 1453/cell and displaying a K$ sb{ rm d}$ = 0.6 $ times$ 10$ sp{-9}$ M. Northern blot analysis of RNA isolated from adluminal germ cells, namely spermatocytes, round spermatids and elongating spermatids, indicated that these cells expressed Tf receptor mRNA and ferritin mRNA in levels inversely related to their stage of maturation. Finally it was determined that following binding and internalization in round spermatids, Tf became associated with the endosomal compartment and was recycled back to the cell surface. Diferric tTf binds to Tf receptor on the surface of adluminal germ cells, is internalized by receptor-mediated endocytosis and the apotTf-Tf receptor complex is recycled back to the cell surface where apotTf is released into the adlumenal fluid.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.60453 |
| Date | January 1991 |
| Creators | Petrie, Robert G. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Anatomy.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001215745, proquestno: AAIMM67609, Theses scanned by UMI/ProQuest. |
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