Linked Life Data

8863840

Source:http://linkedlifedata.com/resource/pubmed/id/8863840

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-11-25
pubmed:abstractText
A polyamine component of Agelenopsis aperta spider venom designated FTX is reported to be a selective antagonist of P-type calcium channels in the mammalian brain. Consequently, this component has frequently been used as a pharmacological tool to determine the presence, distribution, and function of P-type channels in physiological systems. We describe antagonism of calcium channels by the synthesized polyamine FTX-3.3, which has the proposed structure of natural FTX. We also examined a corresponding polyamine amide, sFTX-3.3. These polyamines are critically evaluated for antagonism of three high-threshold calcium channel subtypes in rat neurons through the use of the whole-cell patch-clamp technique. FTX-3.3 (IC50 = approximately 0.13 mM) is approximately twice as potent as sFTX-3.3 (IC50 = approximately 0.24 mM) against P-type channels and approximately 3-fold more potent against N-type channels (FTX-3.3, IC50 = approximately 0.24 mM; sFTX-3.3, IC50 = approximately 0.70 mM). Both polyamines also block L-type calcium channels with similar potencies. sFTX-3.3 (1 mM) and FTX-3.3 (0.5 mM) typically block 50% and 65% of Bay K8644-enhanced L-type current, respectively. Antagonism of each calcium channel subtype is voltage dependent, with less inhibition of Ba2+ currents at more-positive potentials. These data show that both sFTX-3.3 and FTX-3.3 antagonize P-, N-, and L-type calcium channels in mammalian Purkinje and superior cervical ganglia neurons with similar IC50 values.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
939-46
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Block of high-threshold calcium channels by the synthetic polyamines sFTX-3.3 and FTX-3.3.
pubmed:affiliation
Department of Entomology, University of California, Riverside 92521, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't