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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-6-8
pubmed:abstractText
The purpose of this study was to test whether the elevated intracellular Ca++ level ([Ca++]i) resulting from store-operated Ca++ entry was associated with vascular smooth muscle contraction. Cyclopiazonic acid (CPA), a selective inhibitor of sarcoplasmic reticulum Ca(++)-ATPase, concentration-dependently (1-10 microM) elevated [Ca++]i in rat aorta, as indicated by an increase in the fura-2 340/380 ratio. Simultaneous measurement of contraction demonstrated that 1 and 10 microM CPA induced insignificant and variable amounts of contraction, respectively. Verapamil (10 microM) had relatively little effect on the 1 and 10 microM CPA-elevated [Ca++]i. In contrast, Ni++ (0.1 mM), in the presence of verapamil, abolished the 1 microM CPA-elevated [Ca++]i. Ni++ (0.1 mM) also partially decreased the 10 microM CPA-elevated [Ca++]i and, furthermore, abolished the associated contraction. A higher Ni++ concentration (1 mM) abolished the 10 microM CPA-elevated [Ca++]i that remained after verapamil and 0.1 mM Ni++. Phorbol dibutyrate (10 nM), a protein kinase C activator, potentiated contractions to 1 and 10 microM CPA in the presence of verapamil. Ni++ (0.1 mM) abolished the enhanced contractions, and decreased the elevated [Ca++]i. These results suggest that 1) elevated [Ca++]i due to store-operated Ca++ entry is dissociated from contraction; 2) the elevated [Ca++]i is restricted to at least two noncontractile compartments that can be differentiated by their relative sensitivities to blockade by low (0.1 mM) and higher (1 mM) Ni++ concentrations, and 3) [Ca++]i elevation within the compartment sensitive to blockade by 0.1 mM Ni++ can be coupled to contraction via protein kinase C activation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
285
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
759-66
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Coupling of store-operated Ca++ entry to contraction in rat aorta.
pubmed:affiliation
Department of Pharmacology and Cell Biophysics, University of Cincinnati, Ohio, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't