| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
2 Department of Neurobiology and Behavior, University of California Irvine, CA 92697-4550, USA
Different cell types show widely divergent mechanisms and kinetics of exocytosis. We investigated these processes in pancreatic acinar cells by using video-rate 2-photon microscopy to image entry of extracellular dye into individual zymogen granules undergoing exocytosis. Fluorescence signals display two distinct phases; an initial peak that then decays over several seconds to a prolonged plateau. Several observations suggest that the first component reflects the binding of dye to the granule contents and their subsequent release into the acinar duct. These observations include: the peak/plateau fluorescence ratio differs between different dyes; the initial fluorescence decay mirrors the loss of granule contents as monitored by differential interference contrast microscopy; and the fall in vesicular fluorescence is accompanied by a rise in fluorescence in the adjacent duct lumen. We thus propose the use of extracellular fluorescent probes as a convenient means to monitor the kinetics of loss of proteinaceous content from secretory granules. In pancreatic acinar cells the fusion pore remains open much longer than required to ensure secretion of the granule contents, and instead the persistent empty ‘ghost-granule’ may act as a conduit to which secondary granules can fuse and release their contents by compound exocytosis.
(Received 11 October 2004;
accepted after revision 23 December 2004;
first published online 6 January 2005)
Corresponding author P. Thorn: Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK. Email: pt207{at}cam.ac.uk
This article has been cited by other articles:
|
|
 |
|
  O. Larina, P. Bhat, J. A. Pickett, B. S. Launikonis, A. Shah, W. A. Kruger, J. M. Edwardson, and P. Thorn Dynamic Regulation of the Large Exocytotic Fusion Pore in Pancreatic Acinar Cells Mol. Biol. Cell, September 1, 2007; 18(9): 3502 - 3511. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Hatakeyama, N. Takahashi, T. Kishimoto, T. Nemoto, and H. Kasai Two cAMP-dependent pathways differentially regulate exocytosis of large dense-core and small vesicles in mouse beta-cells J. Physiol., August 1, 2007; 582(3): 1087 - 1098. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Vardjan, M. Stenovec, J. Jorgacevski, M. Kreft, and R. Zorec Subnanometer Fusion Pores in Spontaneous Exocytosis of Peptidergic Vesicles J. Neurosci., April 25, 2007; 27(17): 4737 - 4746. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. A. Rutter and E. V. Hill Insulin Vesicle Release: Walk, Kiss, Pause ... Then Run Physiology, June 1, 2006; 21(3): 189 - 196. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Sokac and W. M. Bement Kiss-and-Coat and Compartment Mixing: Coupling Exocytosis to Signal Generation and Local Actin Assembly Mol. Biol. Cell, April 1, 2006; 17(4): 1495 - 1502. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Kasai, H. Hatakeyama, T. Kishimoto, T.-T. Liu, T. Nemoto, and N. Takahashi A new quantitative (two-photon extracellular polar-tracer imaging-based quantification (TEPIQ)) analysis for diameters of exocytic vesicles and its application to mouse pancreatic islets J. Physiol., November 1, 2005; 568(3): 891 - 903. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Chen, J. D. Warner, D. I. Yule, and D. R. Giovannucci Spatiotemporal analysis of exocytosis in mouse parotid acinar cells Am J Physiol Cell Physiol, November 1, 2005; 289(5): C1209 - C1219. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
