In vitro studies will contribute significantly to an understanding of cell growth and differentiation in the adult pancreas. This thesis reports on the changes occurring when acinar cells, terminal ducts and islets are grown in culture. / A number of methods for adult pancreatic duct epithelial isolation and culture from different species have been reported. However, there are no reliable methods for the large scale isolation and culture of the terminal segments of the pancreatic duct system. Acinar fragments of the hamster pancreas are isolated by partial digestion with collagenase. Culture is achieved by embedding in a matrix of rat-tail collagen in DME:F12 medium and 10% NuSerum supplemented with epidermal growth factor (EGF) and cholera toxin (CT). The results show that ductal cysts arise within the areas of degenerated acinar tissue. The method developed in the preparation of this thesis gave a high yield of ductal cysts. Autoradiography indicates the duct cysts could have originated from either progenitor cells of ducts or those of acini. In addition, the question of whether these duct epithelial cysts originate from phenotypic transformation of acinar cells needs to be further evaluated. / Acinar fragments isolated from the hamster pancreas were embedded in type 1 collagen and grown in various media. After 34 days in culture, up to 80% of the acinar cells can be shown to be normal, while the remainder were severely degenerated. This occurred in media to which EGF and CT had not been added. When the latter were added, cystic structures developed. However, a few of the cells within the cystic wall still showed amylase positive immuno-reactivity. Cellular amylase activity decreased over time but a more rapid decline was shown in cells cultured with Media containing EGF and CT. It was also found that the duct-like cells had a limited capacity to redifferentiate into acinar cells. This study suggests that ductal-like epithelial structures may arise from transformation of acinar cells and/or proliferation of ductal cells. / Purified islets from human pancreas were placed into collagen gel matrix and cultured in DME:F12 medium and 10% NuSerum supplemented with EGF and CT. The results showed that the cultured islets underwent a cystic transformation that was associated with (i) a progressive loss of insulin gene expression, (ii) a loss of immunoreactivity for insulin protein, and (iii) the appearance of CK-19, a marker for ductal cells. After the transformation was complete, the cells had the ultrastructural appearance of primitive duct-like cells. Cysts showed a progressive enlargement with cell replication, as reflected in a 1500% increase in the incorporation of tritiated thymidine. These results are consistent with the transdifferentiation of islet cells to ductal cells.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.34485 |
| Date | January 1997 |
| Creators | Yuan, Songyang. |
| Contributors | Duguid, W. P. (advisor) |
| 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 Pathology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001559023, proquestno: NQ30425, Theses scanned by UMI/ProQuest. |
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