Linked Life Data

2381767

Source:http://linkedlifedata.com/resource/pubmed/id/2381767

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1990-9-12
pubmed:abstractText
Single sinus venosus cells from frog, Rana esculenta, were isolated using an enzymic dispersion procedure, involving applications of collagenase and protease. About 40%-60% of the cells showed spontaneous contractions. Isolated cells were studied in the whole-cell configuration. Regenerative action potentials were tetrodotoxin-insensitive and similar to those recorded in multicellular preparations. Hyperpolarizing pulses in the voltage range negative to -50 mV induced the activation of a time-dependent inward current, which was blocked by 4 mM caesium but less affected by barium ions. A lower concentration of caesium (1 mM) exerted a voltage-dependent reduction of the current and decreased the spontaneous pacing rate. The activation range of the hyperpolarization-activated current approximately extended from -50 mV to -110 mV, but varied from cell to cell. A high variability was observed in the behaviour of the activation kinetics. The current had a reversal potential near -20 mV that was shifted positively by increasing the external potassium concentration (from 3 mM to 30 mM) and negatively by reducing the external sodium concentration (from 115 mM to 30 mM). The hyperpolarization-activated inward current of the frog sinus venosus cell appears to be carried by both sodium and potassium ions. It shows electrophysiological properties similar to those of the If current of the mammalian heart. The role of the current in the spontaneous activity is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
416
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
339-46
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Isolated cells of the frog sinus venosus: properties of the inward current activated during hyperpolarization.
pubmed:affiliation
Laboratoire de Physiologie Générale, U.R.A. CNRS no 290, Faculté des Sciences, Université de Poitiers, France.
pubmed:publicationType
Journal Article