Synaptic like microvesicles : Do they participate in regulated exocytosis?

• Published in: Neurochemistry international Vol. 27; no. 3; pp. 219 - 226
• Main Author: Llona, Isabel
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-09-1995; Elsevier
• Subjects: Acetylcholine - metabolism; Adrenal Medulla - physiology; Animals; Biological and medical sciences; Cell physiology; Exocytosis - physiology; Fundamental and applied biological sciences. Psychology; gamma-Aminobutyric Acid - metabolism; Humans; Islets of Langerhans - physiology; Membrane Proteins - metabolism; Molecular and cellular biology; Nerve Endings - physiology; Neurosecretory Systems - physiology; Organelles - physiology; Pituitary Gland - physiology; Secretion. Exocytosis; Synaptic Vesicles - physiology; Synaptic vesicle; Endocrine cell; Review; Exocytosis; Neurosecretion
• ISSN: 0197-0186; 1872-9754
• DOI: 10.1016/0197-0186(95)00005-S

Synaptic like microvesicles (SLMV) form a pleiomorphic population of vesicles present in neuroendocrine cells of the pituitary and the adrenal medulla. Their composition and biogenesis is very similar to small synaptic vesicles (SSV) present in nerve terminals. Membrane proteins of SSV involved in fusion (synaptotagmin) and trafficking (Rab 3) together with synaptophysin have been identified on SLMV. The SLMV from pancreatic beta cells store GABA, those present in chromaffin cells catecholamines and/or acetylcholine. We conclude that SLMV may participate in regulated exocytosis based on (a) their localization near release sites, (b) their content and (c) their membrane composition. The functional meaning and the way this process is regulated remain to be elucidated.