Linked Life Data

2409520

Source:http://linkedlifedata.com/resource/pubmed/id/2409520

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1985-8-19
pubmed:abstractText
Voltage clamp experiments were done on single myelinated nerve fibres of the frog, Rana esculenta, with 10 mM TEA+ in the external solutions to block potassium channels. Sodium current inactivation was measured in TEA-Ringer solution and after treatment with Anemonia sulcata toxin II (5 microM), internal iodate (20/40 mM), glutaraldehyde (10 mM), chloramine-T (0.6 mM), and 2,4,6-trinitrophenol (1 mM). The diphasic inactivation time course, observed in untreated membranes, is slowed by all these agents in a very similar way. Both time constants are increased and the proportion of inactivation components is changed favouring the slowly inactivating one. Trinitrophenol only slows inactivation, whereas in Anemonia toxin II, internal iodate, glutaraldehyde and chloramine-T inactivation becomes incomplete, so that a persistent current is flowing during depolarizations. None of these agents even at high concentrations however, totally removes inactivation. These modifications of inactivation time course are interpreted as changes of rate constants in a three-state inactivation model with one open and two closed states (o-c-c). After chemical treatment the access to the closed states is impeded and the transitions into the open state are accelerated. If the membrane is depolarized during drug application chloramine-T fails to modify inactivation. The curve relating the steady state inactivation parameter, h infinity, to the conditioning potential, V pp becomes non-monotonic in chloramine-T, i.e. dh infinity/dV pp greater than 0 for V pp greater than 60 mV. Trinitrophenol, which per se fails to produce a persistent current component, increases the persistent current in a fibre pretreated with chloramine-T.(ABSTRACT TRUNCATED AT 250 WORDS)
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
404
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Behaviour of chemically modified sodium channels in frog nerve supports a three-state model of inactivation.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't