For two decades, multiple observations of nonparallel pancreatic secretion, wherein digestive enzyme proportions change rapidly following various digestive stimuli, have conflicted with the concept of exocrine pancreatic homogeneity and the exocytosis model of parallel synthesis, transport and secretion of proteins. Evidence of pancreatic heterogeneity is presented, potentially resolving this longstanding controversy. Correlation and regression analysis simultaneously demonstrated exocytosis and nonparallel secretion, suggesting the existence of multiple heterogeneous exocytotic pathways. Next, heterogeneous prestored pancreatic protein sources were directly demonstrated using double isotopic labelling; temporal and secretagogue-specific regulation of the heterogeneous secretory sources was uncovered. Finally, specific enzyme proportions were linked to the heterogeneous sources by densitometric measurements of electrophoretic gels of secreted proteins. Thus, it appears that differential secretion from heterogeneous sources of prestored secretory proteins containing unique proportions of digestive enzymes is the basis of regulated nonparallel secretion in the exocrine pancreas.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.74316 |
| Date | January 1989 |
| Creators | Miller, Paul E. |
| 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 Physiology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001233165, proquestno: AAINN63602, Theses scanned by UMI/ProQuest. |
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