Recycling of intact dense core vesicles in neurites of NGF-treated PC12 cells.
Exocytic fusion in neuroendocrine cells does not always result in complete release of the peptide contents from dense core vesicles (DCVs). In this study, we use fluorescence imaging and immunoelectron microscopy to examine the retention, endocytosis and recycling of chromogranin B in DCVs of NGF-treated PC12 cells. Our results indicate that DCVs retained and retrieved an intact core that was available for subsequent exocytic release. The endocytic process was inhibited by cyclosporine A or by substitution of extracellular Ca(2+) with Ba(2+) and the total recycling time was less than 5 min.
Department of Biological Sciences, University of Denver, 2190 E. Iliff Avenue, Denver, CO 80208, USA.
Roslyn A
RA
Bauer
Rebecca S
RS
Khera
Janet L
JL
Lieber
Joseph K
JK
Angleson
D000818:Animals; D001464:Barium / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology; D004705:Endocytosis / Q000187:drug effects; D005089:Exocytosis / Q000187:drug effects / Q000502:physiology; D020932:Nerve Growth Factor / Q000494:pharmacology*; D016501:Neurites / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D016716:PC12 Cells; D051381:Rats
D002413:Cations, Divalent; D001464:Barium; D016572:Cyclosporine; D020932:Nerve Growth Factor; D002118:Calcium