rdf:type |
|
lifeskim:mentions |
|
pubmed:issue |
1
|
pubmed:dateCreated |
1993-12-13
|
pubmed:abstractText |
The effects of calphostin A on cytoplasmic calcium levels, receptor-mediated calcium release, and membrane input resistance were measured in neuroblastoma cells. Calphostin A is a lipophilic, light-sensitive perylenequinone that generates singlet oxygen when illuminated. It inhibits the activity of protein kinase C (IC50 = 250 nM), but only in the presence of light. Phorbol esters normally attenuate carbachol-evoked calcium release. This effect was blocked by simultaneous exposure to light and calphostin A (40 nM) for 30 min. At higher doses (0.5-1 microM) calphostin A also approximately doubled the resting calcium level and decreased cell input resistance by 51%. These toxic effects did not occur in the dark or after preincubation with the antioxidant alpha-tocopherol. These data support the hypothesis that the calphostins act by partitioning into the membrane and producing singlet oxygen and endoperoxides which then irreversibly modify protein kinase C and other membrane proteins and lipids.
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pubmed:grant |
|
pubmed:language |
eng
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pubmed:journal |
|
pubmed:citationSubset |
IM
|
pubmed:chemical |
|
pubmed:status |
MEDLINE
|
pubmed:month |
Jul
|
pubmed:issn |
0304-3940
|
pubmed:author |
|
pubmed:issnType |
Print
|
pubmed:day |
9
|
pubmed:volume |
157
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
25-8
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pubmed:dateRevised |
2007-11-15
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pubmed:meshHeading |
pubmed-meshheading:7694190-Animals,
pubmed-meshheading:7694190-Calcium,
pubmed-meshheading:7694190-Carbachol,
pubmed-meshheading:7694190-Free Radicals,
pubmed-meshheading:7694190-Fura-2,
pubmed-meshheading:7694190-Homeostasis,
pubmed-meshheading:7694190-Membranes,
pubmed-meshheading:7694190-Mice,
pubmed-meshheading:7694190-Naphthalenes,
pubmed-meshheading:7694190-Neuroblastoma,
pubmed-meshheading:7694190-Polycyclic Compounds,
pubmed-meshheading:7694190-Protein Kinase C,
pubmed-meshheading:7694190-Reactive Oxygen Species,
pubmed-meshheading:7694190-Tumor Cells, Cultured,
pubmed-meshheading:7694190-Vitamin E
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pubmed:year |
1993
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pubmed:articleTitle |
Membrane toxicity of the protein kinase C inhibitor calphostin A by a free-radical mechanism.
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pubmed:affiliation |
Department of Biological Sciences, Stanford University, Pacific Grove, CA 93950.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|