Linked Life Data

9888301

Source:http://linkedlifedata.com/resource/pubmed/id/9888301

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-4-1
pubmed:abstractText
Brain ischemia stimulates release from astrocytes of adenine-based purines, particularly adenosine, which is neuroprotective. Guanosine, which has trophic properties that may aid recovery following neurological damage, is present in high local concentrations for several days after focal cerebral ischemia. We investigated whether guanine-based purines, like their adenine-based counterparts, were released from astrocytes and whether their release increased following hypoxia/hypoglycemia. HPLC analysis of culture medium of rat astrocytes showed spontaneous release of endogenous guanine-based purines at a higher rate than their adenine-based counterparts. The concentration of guanosine (approximately 120 nM) and adenosine (approximately 43 nM) in the culture medium remained constant, whereas concentrations of adenine and guanine nucleotides, particularly GMP, and their metabolites increased with time. Exposure of the cultures to hypoxia/hypoglycemia for 30 min increased the extracellular concentration of adenine-based purines by 2.5-fold and of guanine-based purines by 3.5-fold. Following hypoxia/hypoglycemia extracellular adenine nucleotide levels increased further. Adenosine concentration increased, but not proportionally to nucleotide levels. Accumulation of adenosine metabolites indicated it was rapidly metabolized. Conversely, the concentrations of extracellular guanine-based nucleotides remained elevated and the concentration of guanosine continued to increase. These data indicate that astrocytes are a major source of guanine-based purines, the release of which is markedly increased following hypoxia/hypoglycemia, permitting them to exert neurotrophic effects.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0894-1491
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
93-8
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Rat cultured astrocytes release guanine-based purines in basal conditions and after hypoxia/hypoglycemia.
pubmed:affiliation
Department of Biomedical Sciences, University of Chieti, Italy. r.ciccarelli@dsb.unich.it
pubmed:publicationType
Journal Article