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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2003-4-11
pubmed:abstractText
In this study, we examined histamine-induced calcium signaling in cultured human valvular myofibroblasts (hVMFs), which are the most prominent interstitial cells in cardiac valves mediating valvular contraction, extracellular matrix secretion, and wound repair. Despite the functional importance of VMFs in cardiac valves, the cellular-signaling pathways, especially those mediated by Ca(2+), are still poorly understood. Using fluorescence imaging microscopy, we measured intracellular Ca(2+) ([Ca(2+)](i)) levels in fura-2-loaded hVMFs. Activation of H(1) receptors released Ca(2+) from one compartment of the endoplasmic reticulum (ER) of hVMFs, but did not induce Ca(2+) entry. This histamine-induced Ca(2+) release was oscillatory and dependent on Ca(2+) re-uptake into the ER by sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA). Application of the reversible SERCA blocker, cyclopiazonic acid (CPA), after depletion of the histamine-sensitive Ca(2+) store revealed the presence of a second, smaller histamine-insensitive Ca(2+) store in the ER. The Ca(2+) content ratio of the histamine-sensitive and histamine-insensitive Ca(2+) stores in the ER was found to be approximately 1.15:1. Another effect of CPA in hVMFs was the activation of store-operated Ca(2+) channels, as demonstrated by maintained [Ca(2+)](i) elevation as well as accelerated Mn(2+) entry. In conclusion, this study establishes for the first time an agonist-induced Ca(2+)-signaling pathway in hVMFs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2828
pubmed:author
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
379-88
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Histamine-induced Ca(2+) signaling in human valvular myofibroblasts.
pubmed:affiliation
Department of Pathology, The iCAPTUR4E Centre, St Paul's Hospital, University of British Columbia, Vancouver, Canada V6T 1Z3.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't