The zymogenic units, which characterize the epithelium in the body region of the mouse stomach, are composed of pit, isthmus, neck and base. Electron microscopy and $ sp3$H-thymidine radioautography have been used to study kinetics of the component cells and obtain an estimate of their life duration. / The isthmus includes four immature cell types: granule free cells which function as stem cells directly giving rise to two other immature cell types named pre-pit and pre-neck cells, while the fourth or pre-parietal cells come from the stem cells and its two descendants. / Pre-pit cells evolve into pit cells, which migrate along the pit while producing dense mucous granules and, in 3 days, reach the surface where they are phagocytosed or extruded to the lumen. Pre-parietal cells become the acid-producing parietal cells, which migrate from the isthmus; about 20% up the pit and the remaining 80%, to the neck. Parietal cells in either pit or base eventually degenerate, die and are phagocytosed or released either to the unit lumen or even into connective tissue spaces after an overall life of 67 days. Pre-neck cells become neck cells which descend along the neck in 40 days while producing cored mucous granules. They then become muco-zymogenic cells, which further transform into the pepsin-producing zymogenic cells. These, after a 256 day mean life, degenerate or are attacked by connective tissue macrophages.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.70182 |
| Date | January 1990 |
| Creators | Karam, Sherif Mohamed |
| 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 | Doctor of Philosophy (Department of Anatomy.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001213504, proquestno: AAINN67589, Theses scanned by UMI/ProQuest. |
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