Linked Life Data

9462701

Source:http://linkedlifedata.com/resource/pubmed/id/9462701

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-2-13
pubmed:abstractText
Quantitative time-resolved measurements of cytosolic Ca2+ release by photolysis of caged InsP3 have been made in single rat submandibular cells using patch clamp whole-cell recording to measure the Ca2+-activated Cl- and K+ currents. Photolytic release of InsP3 from caged InsP3 at 100 Joules caused transient inward (V(H) = 60 mV) and outward (V(H) = 0 mV) currents, which were nearly symmetric in their time course. The inward current was reduced when pipette Cl- concentration was decreased, and the outward current was suppressed by K+ channel blockers, indicating that they were carried by Cl- and K+, respectively. Intracellular pre-loading of the InsP3 receptor antagonist heparin or the Ca2+ chelator EGTA clearly prevented both inward and outward currents, indicating that activation of Ca2+-dependent Cl- and K+ currents underlies the inward and the outward currents. At low flash intensities, InsP3 caused Ca2+ release which normally activated the K+ and Cl- currents in a mono-transient manner. At higher intensities, however, InsP3 induced an additional delayed outward K+ current (I[K,(delay)]). I[K(delay)] was independent of the initial K+ current, independent of extracellular Ca2+, inhibited by TEA, and gradually prolongated by repeated flashes. The photolytic release of Ca2+ from caged Ca2+ did not mimic the I[K(delay)]. It is suggested that Ca2+ releases from the InsP3-sensitive pools in an InsP3 concentration-dependent manner. Low concentrations of InsP3 induce the transient Ca2+-dependent Cl- and K+ currents, which reflects the local Ca2+ release, whereas high concentrations of InsP3 induce a delayed Ca2+-dependent K+ current, which may reflect the Ca2+ wave propagation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
387-97
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Kinetics of Ca2+ release evoked by photolysis of caged InsP3 in rat submandibular cells.
pubmed:affiliation
Department of Physiology, Hirosaki University School of Medicine, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't