2015
Volume 15, Number 1, pp. 15-18
High resolution detail of differences between the exocrine pancreas porosome and the neuronal porosome
M. Suciu,1 C. Craciun2 and L. Barbu-Tudoran2
1Department of Natural Sciences, Engineering and Computer Science, Western University “Vasile Goldis”, 80-86 Rebreanu St, Arad, Romania
2Electron Microscopy Centre, Department of Biology, Babes-Bolyai University, 5-7 Clinicilor St, 400006 Cluj-Napoca, Romania
Porosomes are permanent cup-shaped lipoprotein structures at the cell plasma membrane, where membrane-bounded secretory vesicles temporarily dock and fuse to expel a portion of their contents during cellular secretion. Porosomes are present in all secretory cells, such as at the nerve terminal for the release of neurotransmitters, at the apical plasma membrane of the exocrine pancreas for secretion of digestive enzymes, and at the plasma membrane of endocrine cells for the release of hormones such as insulin. Porosome size varies within and between cells. In the exocrine pancreas, endocrine cells, or in the mucin-secretory cells of the airway epithelia, porosomes are 100–180 nm in diameter. In contrast, porosomes in neurons and astrocytes are only 12–15 nm. This paper reviews the differences between the pancreatic and neural porosome, exemplified with images from our laboratory.
Keywords: exocytosis, neuron, pancreas, porosome