Linked Life Data

12164305

Source:http://linkedlifedata.com/resource/pubmed/id/12164305

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2002-8-7
pubmed:abstractText
Much evidence suggests that caffeine/ryanodine (Caf/Ry)-releasable and inositol-1,4,5-trisphosphate (InsP3)-releasable Ca2+ stores in the sarcoplasmic reticulum (SR) of smooth muscles are at least partially distinct. We directly visualized SR stores in primary-cultured rat mesenteric artery myocytes with high-resolution digital imaging and the low-affinity Ca2, indicator, Furaptra (Kd = 75.6 microM). The SR appears to be a continuous tubular network. Nevertheless, SR Ca2+ stores are organized into small, separate, functionally independent compartments. Cyclopiazonic acid (CPA; inhibits SR (Ca2+ pump) and Caf (or Ry) release Ca2+ from different, spatially distinct compartments. Similar heterogeneity is seen with serotonin (acts via InsP3), which unloads only the CPA-sensitive compartments. Some of the SR ('junctional' SR; jSR) lies within 12-15 nm of the plasmalemma (PL). The jSR, the overlying PL microdomains, and the intervening, tiny volume of cytosol form junctional complexes ('PLasmERosomes'). Na+ pumps with high-ouabain-affinity alpha2 or alpha3 subunits, Na+/Ca2+ exchangers, and store-operated channels are confined to these PL microdomains, whereas Na+ pumps with low-ouabain-affinity alpha1 subunits and plasma membrane Ca2+ pumps are uniformly distributed. As a result of this organization, low-dose ouabain can selectively modulate Na+ and Ca2+ concentrations in the PLasmERosomes and jSR Ca2+ stores, and can thereby regulate Ca2+ signalling.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1528-2511
pubmed:author
pubmed:issnType
Print
pubmed:volume
246
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
125-37; discussion 137-41, 221-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Organization of Ca2+ stores in vascular smooth muscle: functional implications.
pubmed:affiliation
Department of Physiology, University of Maryland School of Medicine, Baltimore 21201, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't