Linked Life Data

2159060

Source:http://linkedlifedata.com/resource/pubmed/id/2159060

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1990-6-6
pubmed:abstractText
Despite their widespread use in investigations of protein kinase C (PKC), concern is often expressed regarding the specificity of action of phorbol esters. We have extensively compared the effects of PDBu, a phorbol ester that activates PKC, with those of its inactive analog, 4 alpha-PDBu, on calcium (Ca) channel regulation in acutely isolated guinea pig hippocampal neurons and found that PKC-dependent and -independent actions could be clearly distinguished. While both phorbol esters depressed whole-cell barium current through Ca channels (IBa), PDBu was approximately 100-fold more potent than 4 alpha-PDBu. PKC-independent effects began to appear in the range of 5-10 microM, doses that, while high, have been used in some investigations. Moreover, only PDBu (1) was active when applied intracellularly, (2) had effects that were blocked by the PKC inhibitor H-7, and (3) induced PKC translocation with potency similar to its potency in depressing IBa. The finding that 4 alpha-PDBu acted only extracellularly was unexpected and suggested either that it acted via an extracellular binding site or that its orientation in the membrane was crucial to its effects on Ca channels. Finally, (4) PDBu alone caused a hyperpolarizing shift in the voltage dependence of the high-voltage-activated, rapidly inactivating (N type) component of Ca current. This result extends our previous finding that the N-type current component was depressed by PDBu to a greater extent than the L-type component and may represent an important new mode of neurotransmitter regulation of ion channels in the brain via PKC.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1699-706
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Protein kinase C-dependent and -independent effects of phorbol esters on hippocampal calcium channel current.
pubmed:affiliation
Department of Physiology, University of Maryland School of Medicine, Baltimore 21201.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't