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Article: Inhibition of vasoconstriction by potassium channel opener aprikalim in human conduit arteries used as bypass grafts

TitleInhibition of vasoconstriction by potassium channel opener aprikalim in human conduit arteries used as bypass grafts
Authors
KeywordsHuman artery
Internal mammary artery
Potassium channel opener
Aprikalim
KATP
Issue Date1997
PublisherBlackwell Publishing Ltd. The Journal's web site is located at http://www.blackwellpublishing.com/journals/BJCP
Citation
British Journal of Clinical Pharmacology, 1997, v. 44 n. 4, p. 353-359 How to Cite?
AbstractAIMS: Potassium channel openers (KCOs) are of potential therapeutic value. Little is known about the effect of these drugs on human conduit arteries used as coronary bypass grafts. The purpose of this study was to determine the effect of the KCO aprikalim (RP52891) on human arteries used as coronary bypass grafts with emphasis on the possible difference in the inhibitory effect on depolarizing agent-mediated rather than receptor-mediated contraction. METHODS: Human internal mammary artery segments (IMA, n = 88) taken from 28 patients were studied. Concentration-relaxation curves for aprikalim were established in IMA precontracted with three vasoconstrictors (K+, U46619, and phenylephrine). In IMA rings incubated with aprikalim (1 or 30 microM) for 10 min concentration-contraction curves for the three vasoconstrictors were constructed. RESULTS: Aprikalim-induced relaxation was less in K+ (37.3 +/- 6.4%) than in U46619 (80.2 +/- 7.7%, P=0.002), or phenylephrine (67.5 +/- 7.0%, P=0.038) -precontracted IMA. The EC50 for K+-(-5.40 +/- 0.12 log M) was significantly higher than that for phenylephrine (-6.43 +/- 0.30 log M, P=0.007) but not significant compared with that for U46619 (-5.81 +/- 0.11, P>0.05). Pretreatment with aprikalim depressed the contraction by phenylephrine from 140.6 +/- 27.6% to 49.3 +/- 14.1% (P=0.002) and shifted the EC50 11.0-fold higher in rings treated with 1 microM aprikalim (P=0.007). Treatment of aprikalim did not significantly reduce the K+ and U46619-induced contraction (P>0.05) but shifted the concentration-contraction curves rightward (2.8-fold higher for K+, P<0.05 and 2.2-fold higher for U46619, P<0.05). CONCLUSIONS: This study demonstrates that aprikalim has vasorelaxant effects in human conduit arteries used as coronary artery bypass grafts contracted by a variety of vasoconstrictors and this effect is vasoconstrictor-selective with greater potency for alpha1-adrenoceptor agonists than for depolarizing agent K+. These findings provide information on the possible use of this KCO in various clinical settings.
Persistent Identifierhttp://hdl.handle.net/10722/49324
ISSN
2015 Impact Factor: 3.83
2015 SCImago Journal Rankings: 1.486
PubMed Central ID
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorHe, GWen_HK
dc.contributor.authorYang, CQen_HK
dc.date.accessioned2008-06-12T06:39:31Z-
dc.date.available2008-06-12T06:39:31Z-
dc.date.issued1997en_HK
dc.identifier.citationBritish Journal of Clinical Pharmacology, 1997, v. 44 n. 4, p. 353-359en_HK
dc.identifier.issn0306-5251en_HK
dc.identifier.urihttp://hdl.handle.net/10722/49324-
dc.description.abstractAIMS: Potassium channel openers (KCOs) are of potential therapeutic value. Little is known about the effect of these drugs on human conduit arteries used as coronary bypass grafts. The purpose of this study was to determine the effect of the KCO aprikalim (RP52891) on human arteries used as coronary bypass grafts with emphasis on the possible difference in the inhibitory effect on depolarizing agent-mediated rather than receptor-mediated contraction. METHODS: Human internal mammary artery segments (IMA, n = 88) taken from 28 patients were studied. Concentration-relaxation curves for aprikalim were established in IMA precontracted with three vasoconstrictors (K+, U46619, and phenylephrine). In IMA rings incubated with aprikalim (1 or 30 microM) for 10 min concentration-contraction curves for the three vasoconstrictors were constructed. RESULTS: Aprikalim-induced relaxation was less in K+ (37.3 +/- 6.4%) than in U46619 (80.2 +/- 7.7%, P=0.002), or phenylephrine (67.5 +/- 7.0%, P=0.038) -precontracted IMA. The EC50 for K+-(-5.40 +/- 0.12 log M) was significantly higher than that for phenylephrine (-6.43 +/- 0.30 log M, P=0.007) but not significant compared with that for U46619 (-5.81 +/- 0.11, P>0.05). Pretreatment with aprikalim depressed the contraction by phenylephrine from 140.6 +/- 27.6% to 49.3 +/- 14.1% (P=0.002) and shifted the EC50 11.0-fold higher in rings treated with 1 microM aprikalim (P=0.007). Treatment of aprikalim did not significantly reduce the K+ and U46619-induced contraction (P>0.05) but shifted the concentration-contraction curves rightward (2.8-fold higher for K+, P<0.05 and 2.2-fold higher for U46619, P<0.05). CONCLUSIONS: This study demonstrates that aprikalim has vasorelaxant effects in human conduit arteries used as coronary artery bypass grafts contracted by a variety of vasoconstrictors and this effect is vasoconstrictor-selective with greater potency for alpha1-adrenoceptor agonists than for depolarizing agent K+. These findings provide information on the possible use of this KCO in various clinical settings.en_HK
dc.format.extent388 bytes-
dc.format.mimetypetext/html-
dc.languageengen_HK
dc.publisherBlackwell Publishing Ltd. The Journal's web site is located at http://www.blackwellpublishing.com/journals/BJCPen_HK
dc.rightsBritish Journal of Clinical Pharmacology. Copyright © Blackwell Publishing Ltd.en_HK
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License-
dc.rightsThe definitive version is available at www.blackwell-synergy.comen_HK
dc.subjectHuman arteryen_HK
dc.subjectInternal mammary arteryen_HK
dc.subjectPotassium channel openeren_HK
dc.subjectAprikalimen_HK
dc.subjectKATPen_HK
dc.titleInhibition of vasoconstriction by potassium channel opener aprikalim in human conduit arteries used as bypass graftsen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0306-5251&volume=44&issue=4&spage=353&epage=359&date=1997&atitle=Inhibition+of+vasoconstriction+by+potassium+channel+opener+aprikalim+in+human+conduit+arteries+used+as+bypass+graftsen_HK
dc.identifier.emailHe, GW: gwhe@hkucc.hku.hken_HK
dc.description.naturepublished_or_final_versionen_HK
dc.identifier.doi10.1046/j.1365-2125.1997.00640.xen_HK
dc.identifier.pmid9354310en_HK
dc.identifier.pmcidPMC2042851en_HK
dc.identifier.hkuros35128-
dc.identifier.isiWOS:A1997YA90100007-

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