Linked Life Data

17935604

Source:http://linkedlifedata.com/resource/pubmed/id/17935604

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-10-15
pubmed:abstractText
Glutamate release induced by mild depolarization was studied in astroglial preparations from the adult rat cerebral cortex, that is acutely isolated glial sub-cellular particles (gliosomes), cultured adult or neonatal astrocytes, and neuron-conditioned astrocytes. K+ (15, 35 mmol/L), 4-aminopyridine (0.1, 1 mmol/L) or veratrine (1, 10 micromol/L) increased endogenous glutamate or [3H]D-aspartate release from gliosomes. Neurotransmitter release was partly dependent on external Ca2+, suggesting the involvement of exocytotic-like processes, and partly because of the reversal of glutamate transporters. K+ increased gliosomal membrane potential, cytosolic Ca2+ concentration [Ca2+]i, and vesicle fusion rate. Ca2+ entry into gliosomes and glutamate release were independent from voltage-sensitive Ca2+ channel opening; they were instead abolished by 2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiurea (KB-R7943), suggesting a role for the Na+/Ca2+ exchanger working in reverse mode. K+ (15, 35 mmol/L) elicited increase of [Ca2+]i and Ca2+-dependent endogenous glutamate release in adult, not in neonatal, astrocytes in culture. Glutamate release was even more marked in in vitro neuron-conditioned adult astrocytes. As seen for gliosomes, K+-induced Ca2+ influx and glutamate release were abolished by KB-R7943 also in cultured adult astrocytes. To conclude, depolarization triggers in vitro glutamate exocytosis from in situ matured adult astrocytes; an aptitude grounding on Ca2+ influx driven by the Na+/Ca2+ exchanger working in the reverse mode.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
103
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1196-207
pubmed:meshHeading
pubmed-meshheading:17935604-Animals, pubmed-meshheading:17935604-Animals, Newborn, pubmed-meshheading:17935604-Astrocytes, pubmed-meshheading:17935604-Calcium, pubmed-meshheading:17935604-Calcium Channels, pubmed-meshheading:17935604-Calcium Signaling, pubmed-meshheading:17935604-Cell Membrane, pubmed-meshheading:17935604-Cells, Cultured, pubmed-meshheading:17935604-Cerebral Cortex, pubmed-meshheading:17935604-Culture Media, Conditioned, pubmed-meshheading:17935604-Exocytosis, pubmed-meshheading:17935604-Glutamic Acid, pubmed-meshheading:17935604-Membrane Fusion, pubmed-meshheading:17935604-Membrane Potentials, pubmed-meshheading:17935604-Potassium, pubmed-meshheading:17935604-Potassium Channel Blockers, pubmed-meshheading:17935604-Rats, pubmed-meshheading:17935604-Rats, Sprague-Dawley, pubmed-meshheading:17935604-Sodium-Calcium Exchanger, pubmed-meshheading:17935604-Synaptosomes, pubmed-meshheading:17935604-Transport Vesicles, pubmed-meshheading:17935604-Veratrine, pubmed-meshheading:17935604-Vesicular Glutamate Transport Proteins
pubmed:year
2007
pubmed:articleTitle
Adult astroglia is competent for Na+/Ca2+ exchanger-operated exocytotic glutamate release triggered by mild depolarization.
pubmed:affiliation
Department of Experimental Medicine, Pharmacology and Toxicology Section, University of Genoa, Genoa, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't