Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2006-4-7
pubmed:abstractText
Spontaneous electrical pacemaker activity occurs in tunica muscularis of the gastrointestinal tract and drives phasic contractions. Interstitial cells of Cajal (ICC) are the pacemaker cells that generate and propagate electrical slow waves. We used Ca(2+) imaging to visualize spontaneous rhythmicity in ICC in the myenteric region (ICC-MY) of the murine small intestine. ICC-MY, verified by colabeling with Kit antibody, displayed regular Ca(2+) transients that occurred after electrical slow waves. ICC-MY formed networks, and Ca(2+) transient wave fronts propagated through the ICC-MY networks at approximately 2 mm/s and activated attached longitudinal muscle fibers. Nicardipine blocked Ca(2+) transients in LM but had no visible effect on the transients in ICC-MY. beta-Glycyrrhetinic acid reduced the coherence of propagation, causing single cells to pace independently. Thus, virtually all ICC-MYs are spontaneously active, but normal activity is organized into propagating wave fronts. Inhibitors of dihydropyridine-resistant Ca(2+) entry (Ni(2+) and mibefradil) and elevated external K(+) reduced the coherence and velocity of propagation, eventually blocking all activity. The mitochondrial uncouplers, FCCP, and antimycin and the inositol 1,4,5-trisphosphate receptor-inhibitory drug, 2-aminoethoxydiphenyl borate, abolished rhythmic Ca(2+) transients in ICC-MY. These data show that global Ca(2+) transients in ICC-MYs are a reporter of electrical slow waves in gastrointestinal muscles. Imaging of ICC networks provides a unique multicellular view of pacemaker activity. The activity of ICC-MY is driven by intracellular Ca(2+) handling mechanisms and entrained by voltage-dependent Ca(2+) entry and coupling of cells via gap junctions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0363-6143
pubmed:author
pubmed:issnType
Print
pubmed:volume
290
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C1411-27
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Spatial and temporal mapping of pacemaker activity in interstitial cells of Cajal in mouse ileum in situ.
pubmed:affiliation
Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural