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Article: Comparison of the sodium currents in normal Purkinje fibres and Purkinje fibres surviving infarction - A pharmacological study

TitleComparison of the sodium currents in normal Purkinje fibres and Purkinje fibres surviving infarction - A pharmacological study
Authors
Issue Date1989
PublisherJohn Wiley & Sons Ltd. The Journal's web site is located at http://www.wiley.com/bw/journal.asp?ref=0007-1188&site=1
Citation
British Journal Of Pharmacology, 1989, v. 97 n. 4, p. 999-1006 How to Cite?
Abstract1. Purkinje fibres surviving infarction showed a lower maximum upstroke velocity (V̇(max)) and a longer action potential duration when compared to normal Purkinje fibres. A reduction in the fast sodium current and an increase in the sodium 'window' current may be responsible for the observed alterations in V̇(max) and action potential duration respectively. 2. Since voltage clamp studies were not feasible, a pharmacological approach was used. The responses to tetrodotoxin (TTX) and lignocaine in normal Purkinje fibres and Purkinje fibres surviving infarction were used to examine the sodium currents in these fibres. 3. V̇(max), an indirect measure of the fast sodium current, was more sensitive to lignocaine in Purkinje fibres surviving infarction than in normal Purkinje fibres. The reduction in V̇(max) by lignocaine was more prominent at the shorter stimulation cycle length. Significant reduction of V̇(max) was observed with the higher concentration of TTX and no differential effect on V̇(max) between normal Purkinje fibres and Purkinje fibres surviving infarction was detected. 4. Reduction of action potential duration in the presence of TTX or lignocaine was used as a measure of the sodium 'window' current. A greater reduction of action potential duration by TTX and lignocaine was observed in normal Purkinje fibres than in Purkinje fibres surviving infarction. 5. The results suggested that the fast sodium current in Purkinje fibres surviving infarction is more sensitive to pharmacological agents with local anaesthetic properties and the prolonged action potential duration in these Purkinje fibres cannot be due to an increase in the sodium 'window' current. The results are compatible with an enhanced effect of antiarrhythmic drugs on V̇(max) and conduction in the ischaemic heart.
Persistent Identifierhttp://hdl.handle.net/10722/170961
ISSN
2015 Impact Factor: 5.259
2015 SCImago Journal Rankings: 2.368
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorBril, Aen_US
dc.contributor.authorKinnaird, AAAen_US
dc.contributor.authorMan, RYKen_US
dc.date.accessioned2012-10-30T06:11:37Z-
dc.date.available2012-10-30T06:11:37Z-
dc.date.issued1989en_US
dc.identifier.citationBritish Journal Of Pharmacology, 1989, v. 97 n. 4, p. 999-1006en_US
dc.identifier.issn0007-1188en_US
dc.identifier.urihttp://hdl.handle.net/10722/170961-
dc.description.abstract1. Purkinje fibres surviving infarction showed a lower maximum upstroke velocity (V̇(max)) and a longer action potential duration when compared to normal Purkinje fibres. A reduction in the fast sodium current and an increase in the sodium 'window' current may be responsible for the observed alterations in V̇(max) and action potential duration respectively. 2. Since voltage clamp studies were not feasible, a pharmacological approach was used. The responses to tetrodotoxin (TTX) and lignocaine in normal Purkinje fibres and Purkinje fibres surviving infarction were used to examine the sodium currents in these fibres. 3. V̇(max), an indirect measure of the fast sodium current, was more sensitive to lignocaine in Purkinje fibres surviving infarction than in normal Purkinje fibres. The reduction in V̇(max) by lignocaine was more prominent at the shorter stimulation cycle length. Significant reduction of V̇(max) was observed with the higher concentration of TTX and no differential effect on V̇(max) between normal Purkinje fibres and Purkinje fibres surviving infarction was detected. 4. Reduction of action potential duration in the presence of TTX or lignocaine was used as a measure of the sodium 'window' current. A greater reduction of action potential duration by TTX and lignocaine was observed in normal Purkinje fibres than in Purkinje fibres surviving infarction. 5. The results suggested that the fast sodium current in Purkinje fibres surviving infarction is more sensitive to pharmacological agents with local anaesthetic properties and the prolonged action potential duration in these Purkinje fibres cannot be due to an increase in the sodium 'window' current. The results are compatible with an enhanced effect of antiarrhythmic drugs on V̇(max) and conduction in the ischaemic heart.en_US
dc.languageengen_US
dc.publisherJohn Wiley & Sons Ltd. The Journal's web site is located at http://www.wiley.com/bw/journal.asp?ref=0007-1188&site=1en_US
dc.relation.ispartofBritish Journal of Pharmacologyen_US
dc.subject.meshAction Potentials - Drug Effectsen_US
dc.subject.meshAnimalsen_US
dc.subject.meshDogsen_US
dc.subject.meshFemaleen_US
dc.subject.meshHeart Conduction System - Metabolismen_US
dc.subject.meshLidocaine - Pharmacologyen_US
dc.subject.meshMaleen_US
dc.subject.meshMyocardial Infarction - Metabolismen_US
dc.subject.meshPurkinje Fibers - Drug Effects - Metabolismen_US
dc.subject.meshSodium Channels - Drug Effects - Metabolismen_US
dc.subject.meshTetrodotoxin - Pharmacologyen_US
dc.titleComparison of the sodium currents in normal Purkinje fibres and Purkinje fibres surviving infarction - A pharmacological studyen_US
dc.typeArticleen_US
dc.identifier.emailMan, RYK:rykman@hkucc.hku.hken_US
dc.identifier.authorityMan, RYK=rp00236en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.doi10.1111/j.1476-5381.1989.tb12554.x-
dc.identifier.pmid2551448-
dc.identifier.scopuseid_2-s2.0-0024802726en_US
dc.identifier.volume97en_US
dc.identifier.issue4en_US
dc.identifier.spage999en_US
dc.identifier.epage1006en_US
dc.identifier.isiWOS:A1989AH75500003-
dc.publisher.placeUnited Kingdomen_US
dc.identifier.scopusauthoridBril, A=7006161753en_US
dc.identifier.scopusauthoridKinnaird, AAA=6603472891en_US
dc.identifier.scopusauthoridMan, RYK=7004986435en_US

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