Dense-core granules in neuroendocrine cells and neurons release their secretory constituents by piecemeal degranulation (review).
The term piecemeal degranulation (PMD) refers to a slow releasing process mediated by vesicular transport of stored secretory granule contents. This form of cell secretion was first proposed for basophils, mast cells and eosinophils, but evidence has begun to accumulate that PMD also occurs in dense-core granules of neuroendocrine cells and neurons. This review summarizes the electron-microscopic evidence that has been gathered in support of this view and also discusses the possible physiological significance of PMD in this class of secretory organelles in comparison with 'full fusion' and 'kiss-and-run' exocytosis.
Crivellato
Enrico
E
Department of Medical and Morphological Research (Section of Anatomy), University of Udine Medical School, I-33100 Udine, Italy. enrico.crivellato@uniud.it
Nico
Beatrice
B
Bertelli
Eugenio
E
Nussdorfer
Gastone G
GG
Ribatti
Domenico
D
D000818:Animals; D015550:Cell Degranulation / Q000502:physiology*; D003594:Cytoplasmic Granules / Q000378:metabolism* / Q000648:ultrastructure; D004702:Endocrine Glands / Q000166:cytology* / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D022142:Secretory Vesicles / Q000378:metabolism* / Q000648:ultrastructure