Linked Life Data

2556581

Source:http://linkedlifedata.com/resource/pubmed/id/2556581

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-1-23
pubmed:abstractText
Elementary Na+ currents were recorded at 19 degrees C during 220-msec lasting step depolarizations in cell-attached and inside-out patches from cultured neonatal rat cardiocytes in order to study the modifying influence of iodate, bromate and glutaraldehyde on single cardiac Na+ channels. Iodate (10 mmol/liter) removed Na+ inactivation and caused repetitive, burst-like channel activity after treating the cytoplasmic channel surface. In contrast to normal Na+ channels under control conditions, iodate-modified Na+ channels attain two conducting states, a short-lasting one with a voltage-independent lifetime close to 1 msec and, likewise tested between -50 and +10 mV, a long-lasting one being apparently exponentially dependent on voltage. Channel modification by bromate (10 mmol/liter) and glutaraldehyde (0.5 mmol/liter) also included the occurrence of two open states. Also, burst duration depended apparently exponentially on voltage and increased when shifting the membrane in the positive direction, but there was no evidence for two bursting states. Chemically modified Na+ channels retain an apparently normal unitary conductance (12.8 +/- 0.5 pS). Of the two substates observed, one of them is remarkable in that it is mostly attained from full-state openings and is very short living in nature; the voltage-independent lifetime was close to 2 msec. Despite removal of inactivation, open probability progressively declined during membrane depolarization. The underlying deactivation process is strongly voltage sensitive but, in contrast to slow Na+ inactivation, responds to a voltage shift in the positive direction with a retardation in kinetics. Chemically modified Na+ channels exhibit a characteristic bursting state much shorter than in DPI-modified Na+ channels, a difference not consistent with the hypothesis of common kinetic properties in noninactivating Na+ channels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:volume
112
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
67-78
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Gating in iodate-modified single cardiac Na+ channels.
pubmed:affiliation
Physiological Institute, University Freiburg, West Germany.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't