Linked Life Data

15653095

Source:http://linkedlifedata.com/resource/pubmed/id/15653095

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-1-17
pubmed:abstractText
The rapid contraction/relaxation cycles of phasic smooth muscles necessitates intracellular calcium cycling at a more rapid rate than that of tonic smooth muscles. Recent studies suggest that sarcoplasmic reticulum calcium handling is an important determinant of portal vein phasic contractions. We evaluated the importance and role of phospholamban, a protein which inhibits the sarcoplasmic reticulum (SR) calcium ATPase (SERCA), in regulating the contractility of the phasic mouse portal vein. PLB gene ablation significantly reduced the basal frequency of spontaneous mechanical activity and increased force development of the portal vein. Cyclopiazonic acid (CPA), an inhibitor of SERCA, did not significantly affect the spontaneous activity of the wild-type (WT) portal vein. CPA (1 microM) eliminated the differences in frequency and force between the PLB-KO and WT, localizing the effects to the SR. The PLB-KO portal vein had a lower resting membrane potential than WT controls. There were no significant differences between WT and KO responses to charybdotoxin (250 nM), indicating that calcium-activated potassium channels do not contribute to altered KO portal vein contractility. While contractile sensitivity to acetylcholine was not different between WT and PLB-KO portal veins, force generated in response to a given concentration of acetylcholine was significantly greater in the PLB-KO portal vein, both in the absence and presence of CPA. Our results confirm that SR activity can play a major role in modulating the frequency of the spontaneous mechanical activity of portal veins and removal of PLB inhibition of the SR calcium ATPase has significant effects on the spontaneous activity of the portal vein.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1537-1891
pubmed:author
pubmed:issnType
Print
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
197-204
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Regulation of the spontaneous contractile activity of the portal vein by the sarcoplasmic reticulum: evidence from the phospholamban gene-ablated mouse.
pubmed:affiliation
Department of Molecular and Cellular Physiology, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267-0576, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural