Linked Life Data

2147857

Source:http://linkedlifedata.com/resource/pubmed/id/2147857

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1991-1-31
pubmed:abstractText
Recently, we have shown that stimulation of [3H]-noradrenaline release from hippocampal slices by 4-aminopyridine (4-AP) is accompanied by an enhancement of the phosphorylation of B-50, a major presynaptic substrate of protein kinase C (PKC). PKC has been implicated in the regulation of transmitter release. In this study, we investigated the effects of 4-AP on B-50 phosphorylation in synaptosomes from rat brain and compared the effects of 4-AP with those of depolarization with K+, in order to gain more insight into the mechanism of action of 4-AP. B-50 phosphorylation was stimulated by incubation with 4-AP for 2 minutes at concentrations ranging from 10 microM to 5 mM. 4-AP (100 microM) stimulated B-50 phosphorylation already within 15 seconds; longer incubations revealed a sustained increase in the presence of 4-AP. B-50 phosphorylation was also stimulated by depolarization with 30 mM K+ for 15 seconds. The effects of both 4-AP or K+ depolarization on B-50 phosphorylation were abolished at low extracellular Ca2+ concentrations. The increase in B-50 phosphorylation induced by 4-AP seemed to be dependent on the state of depolarization, since the effect of 4-AP was largest under nondepolarizing conditions. Comparing the effects of 4-AP and K+ depolarization on B-50 phosphorylation suggests that a different mechanism of action is involved. These results indicate that the stimulation of B-50 phosphorylation by 4-AP in hippocampal slices can be attributed to a direct action of 4-AP on presynaptic terminals. In addition, our results support the hypothesis that B-50 phosphorylation by PKC is involved in Ca2(+)-dependent transmitter release evoked by 4-AP.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0895-8696
pubmed:author
pubmed:issnType
Print
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
4-Aminopyridine stimulates B-50 (GAP-43) phosphorylation in rat synaptosomes.
pubmed:affiliation
Division of Molecular Neurobiology, Rudolf Magnus Institute, University of Utrecht, The Netherlands.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't