Linked Life Data

18727112

Source:http://linkedlifedata.com/resource/pubmed/id/18727112

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-1-13
pubmed:abstractText
Recently, suggestive evidence for piecemeal degranulation (PMD), a particulate pattern of cell secretion accomplished by vesicle-mediated extracellular transport of granule-stored material, has been provided by electron microscopy investigations in chromaffin cells of different vertebrate species. In this study, chromaffin tissue from the interrenal gland of the amphibian urodede Triturus carnifex has been investigated by quantitative transmission electron microscopy in search for ultrastructural clues indicative of a vesicle-mediated mode of cell degranulation. Interestingly, a single type of chromaffin cell is recognizable in T. carnifex, which undergoes seasonal variations in its adrenaline and noradrenaline granule ratio according to an annual cycle that matches the trend of changes in secondary sexual characters. In this study, we looked for a series of ultrastructural changes regarded as highly specific for PMD. We calculated the percentage of (i) resting, unaltered granules (type 1 granules); (ii) granules with changes indicative of progressive release of secretory materials, that is, granules with lucent areas in their cores, reduced electron density, disassembled matrices, and residual cores (type 2 granules); and (iii) membrane empty containers (type 3 granules) in chromaffin cells of T. carnifex during the annual cycle. We found a significant increase in type 2 and 3 granules, accompanied by a significant decrease in type 1 granules, in the April and November samples. During the same seasonal periods, the number per net cytoplasmic area of 30-100-nm diameter electron-dense vesicles was found to be significantly augmented, and there was also an augmented percentage of chromaffin granules showing blebs or protrusions in their profiles. These ultrastructural data are indicative of an increased vesicle-mediated transport of chromaffin granule products for extracellular release in the amphibian T. carnifex in accordance with the increased rate of catecholamine release. This vesicle-mediated pattern of cell secretion suits the schema of PMD. In an evolutionary perspective, these findings suggest that PMD is a secretory pathway that has been highly conserved throughout vertebrate classes. Anat Rec, 2009. (c) 2008 Wiley-Liss, Inc.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1932-8494
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
292
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
73-8
pubmed:dateRevised
2009-12-16
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Chromaffin cells in the amphibian urodele Triturus carnifex show ultrastructural features indicative of a vesicle-mediated mode of cell degranulation.
pubmed:affiliation
Department of Medical and Morphological Research, Section of Anatomy, University of Udine School of Medicine, Udine, Italy. enrico.crivellato@uniud.it
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't