International Journal of Pancreatology

, Volume 3, Issue 6, pp 409–414 | Cite as

The asynchronous transport of secretory proteins in the exocrine pancreas. Compatibility with the hypothesis of a paragranular pathway?

  • Adrien R. Beaudoin


An asynchronous transport of individual secretory proteins has been recently described in the pancreas This asynchrony was observed in both unstimulated and stimulated conditions. It has also been proposed that unstimulated and stimulated secretions correspond to distinct secretory processes. Indeed according to that hypothesis, under resting conditions, a small fraction of the newly synthesized secretory proteins are channeled into a paragranular (vesicle) pathway while the residual proteins are packaged in the zymogen granules. These zymogen granules eventually move to the cell surface where their content is extruded by exocytosis. Under stimulated conditions the latter process is accelerated. Since the same type of asynchrony is observed under resting and stimulated conditions in the pancreatic juice, one can wonder if the hypothesis of a paragranular pathway is compatible with the observed asynchrony. In this review, an explantion is presented to account for the facts that following pulse and chase labelling, two waves of labelled proteins are released under resting secretions and secondly that asynchrony is maintained in both resting and stimulated conditions.

Key words

Zymogen granule Secretion Pulse-labelling, Intracellular pathway 


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Copyright information

© Elsevier Science Publishers B.V. (Biomedical Division) 1988

Authors and Affiliations

  • Adrien R. Beaudoin
    • 1
  1. 1.Centre de recherche sur les mécanismes de sécrétion, Faculté des scienceUniversité de SherbrookeSherbrookeCanada

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