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Article: In vitro effects of S.3341 on the spontaneous contractile activity of the rat portal vein: Interference with the α-adrenergic stimulation

TitleIn vitro effects of S.3341 on the spontaneous contractile activity of the rat portal vein: Interference with the α-adrenergic stimulation
Authors
Issue Date1988
Citation
Archives Internationales De Pharmacodynamie Et De Therapie, 1988, v. 296, p. 29-44 How to Cite?
AbstractThe aim of this study was to evaluate the α1-adrenoceptor properties of S.3341, a new α-adrenoceptor agonist. Experiments were performed by recording isometric tension of the rat portal vein. pD2 values and apparent intrinsic efficacy of α-adrenoceptor agonists (S.3341, norepinephrine, phenylephrine and clonidine) were assessed from cumulative concentration-response curves. Particular attention was paid to the variations in the amplitude of spontaneous contractions and the increase in the tonus of the vein induced by these agonists. The rank order of activity (pD2 values) of these agonists on the amplitude of spontaneous contractions and on the tonus was as follows: norepinephrine ≥ phenylephrine > clonidine > S.3341. The activity of S.3341 on spontaneous contractions of the vein was found to be of the α1-type only at concentrations higher than 10-6 M. This concentration-dependent effect was antagonized by prazosin but not by rauwolscine. For concentrations lower than 10-6 M, S.3341 decreased the amplitude of spontaneous contractions. This effect was not modified by prazosin or rauwolscine and was affected (decreased) after treatment of the vein with 6-hydroxydopamine (6-OHDA). S.3341 was barely able to increase the tonus of the vein, whatever the concentration used. Moreover, S.3341 was able to antagonize the increase in amplitude of spontaneous contraction and tonus of the vein induced by clonidine and phenylephrine. The effect of S.3341 on the slow inward calcium current was also tested and no effect was found, even at high concentrations. The results suggest that in the rat portal vein, S.3341 is a weak partial α-adrenoceptor agonist which exhibits a quite novel property not related to an adrenergic stimulation or a calcium entry blocking property. The mechanism of this novel effect remains to be elucidated.
Persistent Identifierhttp://hdl.handle.net/10722/171526
ISSN
1998 Impact Factor: 0.72
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorBourreau, JPen_US
dc.contributor.authorFeletou, Men_US
dc.contributor.authorTricoche, Ren_US
dc.date.accessioned2012-10-30T06:15:32Z-
dc.date.available2012-10-30T06:15:32Z-
dc.date.issued1988en_US
dc.identifier.citationArchives Internationales De Pharmacodynamie Et De Therapie, 1988, v. 296, p. 29-44en_US
dc.identifier.issn0003-9780en_US
dc.identifier.urihttp://hdl.handle.net/10722/171526-
dc.description.abstractThe aim of this study was to evaluate the α1-adrenoceptor properties of S.3341, a new α-adrenoceptor agonist. Experiments were performed by recording isometric tension of the rat portal vein. pD2 values and apparent intrinsic efficacy of α-adrenoceptor agonists (S.3341, norepinephrine, phenylephrine and clonidine) were assessed from cumulative concentration-response curves. Particular attention was paid to the variations in the amplitude of spontaneous contractions and the increase in the tonus of the vein induced by these agonists. The rank order of activity (pD2 values) of these agonists on the amplitude of spontaneous contractions and on the tonus was as follows: norepinephrine ≥ phenylephrine > clonidine > S.3341. The activity of S.3341 on spontaneous contractions of the vein was found to be of the α1-type only at concentrations higher than 10-6 M. This concentration-dependent effect was antagonized by prazosin but not by rauwolscine. For concentrations lower than 10-6 M, S.3341 decreased the amplitude of spontaneous contractions. This effect was not modified by prazosin or rauwolscine and was affected (decreased) after treatment of the vein with 6-hydroxydopamine (6-OHDA). S.3341 was barely able to increase the tonus of the vein, whatever the concentration used. Moreover, S.3341 was able to antagonize the increase in amplitude of spontaneous contraction and tonus of the vein induced by clonidine and phenylephrine. The effect of S.3341 on the slow inward calcium current was also tested and no effect was found, even at high concentrations. The results suggest that in the rat portal vein, S.3341 is a weak partial α-adrenoceptor agonist which exhibits a quite novel property not related to an adrenergic stimulation or a calcium entry blocking property. The mechanism of this novel effect remains to be elucidated.en_US
dc.languageengen_US
dc.relation.ispartofArchives Internationales de Pharmacodynamie et de Therapieen_US
dc.subject.meshAdrenergic Alpha-Agonists - Pharmacologyen_US
dc.subject.meshAnimalsen_US
dc.subject.meshCalcium Channel Blockersen_US
dc.subject.meshClonidine - Pharmacologyen_US
dc.subject.meshHydroxydopamines - Pharmacologyen_US
dc.subject.meshIsometric Contraction - Drug Effectsen_US
dc.subject.meshMaleen_US
dc.subject.meshMuscle Contraction - Drug Effectsen_US
dc.subject.meshMuscle, Smooth, Vascular - Drug Effectsen_US
dc.subject.meshNorepinephrine - Pharmacologyen_US
dc.subject.meshOxazoles - Pharmacologyen_US
dc.subject.meshOxidopamineen_US
dc.subject.meshPhenylephrine - Pharmacologyen_US
dc.subject.meshPortal Vein - Drug Effectsen_US
dc.subject.meshRatsen_US
dc.subject.meshRats, Inbred Strainsen_US
dc.subject.meshReceptors, Adrenergic, Alpha - Drug Effectsen_US
dc.titleIn vitro effects of S.3341 on the spontaneous contractile activity of the rat portal vein: Interference with the α-adrenergic stimulationen_US
dc.typeArticleen_US
dc.identifier.emailBourreau, JP:bourreau@hkucc.hku.hken_US
dc.identifier.authorityBourreau, JP=rp00389en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.pmid2907280-
dc.identifier.scopuseid_2-s2.0-0024211849en_US
dc.identifier.volume296en_US
dc.identifier.spage29en_US
dc.identifier.epage44en_US
dc.identifier.isiWOS:A1988R370200003-
dc.identifier.scopusauthoridBourreau, JP=7003927886en_US
dc.identifier.scopusauthoridFeletou, M=7006461826en_US
dc.identifier.scopusauthoridTricoche, R=6603907602en_US

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