title: Ultrastructure of the human APUD cells.
abstract: The present article summarises the results of our studies on the ultrastructure of the APUD cells at an early embryonic stage of development. Twenty eight 8-week-old human embryos were selected. The early forms of the APUD cells in the epithelium of certain embryonic organs of endoblast origin, i.e., stomach, small intestine, liver and lung (bronchi), were distinguished and examined by transmission electron microscopy. The ultrastructure of these premature cells was compared with the ultrastructure of mature APUD cells from adult human organisms. Differences regarding number, size and location of the secretory granules were established. The form and ultrastructure of the granules were found to be identical in both cell types studied. The ultrastructural characteristics and identification of the embryonic APUD cells may serve as a reliable criterion in complex morphological explorations of the human prenatal development.
authors.affiliation: Department of Histology and Embryology, Higher Medical Institute, Plovdiv, Bulgaria.
authors.forename: V
authors.initials: V
authors.lastname: Berbenkova
mesh_terms: D001078:APUD Cells / Q000648:ultrastructure*; D000328:Adult; D001980:Bronchi / Q000196:embryology / Q000648:ultrastructure; D004622:Embryo, Mammalian / Q000648:ultrastructure; D005865:Gestational Age; D006801:Humans; D007421:Intestine, Small / Q000196:embryology / Q000648:ultrastructure; D008099:Liver / Q000196:embryology / Q000648:ultrastructure; D008854:Microscopy, Electron; D013270:Stomach / Q000196:embryology / Q000648:ultrastructure