Effects of ischaemia, reperfusion and α1-adrenergic receptor stimulation on the inositoltrisphosphate receptor population in rat heart atria and ventricles

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dc.contributor.authorHuisamen B.
dc.contributor.authorMouton R.
dc.contributor.authorOpie L.H.
dc.contributor.authorLochner A.
dc.date.accessioned2011-05-15T16:00:01Z
dc.date.available2011-05-15T16:00:01Z
dc.date.issued1994
dc.description.abstractBinding sites specific for inositol 1,4,5-trisphosphate (InsP3) have been demonstrated in sarcoplasmic reticulum vesicles isolated from heart muscle. Scatchard analysis of a binding isotherm indicated a high as well as a low affinity binding site [1]. In this study a comparison was made between InsP3 binding to crude microsomal membranes prepared from rat heart atria and ventricles respectively. Results obtained showed a four-fold higher incidence of binding to atrial membranes. Furthermore, the receptor populations of the atria and ventricles behaved differently during conditions causing fluctuations in tissue InsP3 levels, viz. ischaemia, reperfusion and α1- adrenergic stimulation. Reperfusion, as well as phenylephrine stimulation, caused an increase in InsP3 levels associated with down-regulation of the ventricular InsP3 receptor population while binding to atrial binding sites was elevated. In the ventricular population this down-regulation was the result of a reduction in B(max) alone with no changes in the Kd values of the high- or the low-affinity binding sites. The reason(s) for the differential response of the atrial and ventricular InsP3 receptor populations to changes in InsP3 levels, remains to be established.
dc.description.versionArticle
dc.identifier.citationMolecular and Cellular Biochemistry
dc.identifier.citation140
dc.identifier.citation1
dc.identifier.issn3008177
dc.identifier.other10.1007/BF00928362
dc.identifier.urihttp://hdl.handle.net/10019.1/11484
dc.subjectalpha 1 adrenergic receptor
dc.subjectinositol trisphosphate
dc.subjectphenylephrine
dc.subjectanimal tissue
dc.subjectarticle
dc.subjectcontrolled study
dc.subjectdissociation constant
dc.subjectheart atrium
dc.subjectheart ventricle
dc.subjectisolated heart
dc.subjectmale
dc.subjectmicrosome membrane
dc.subjectnonhuman
dc.subjectrat
dc.subjectreceptor binding
dc.subjectreceptor down regulation
dc.subjectreperfusion injury
dc.subjectsarcoplasmic reticulum
dc.subjectAnimal
dc.subjectCalcium Channels
dc.subjectCell Membrane
dc.subjectComparative Study
dc.subjectHeart Atrium
dc.subjectHeart Ventricle
dc.subjectInositol 1,4,5-Trisphosphate
dc.subjectKinetics
dc.subjectMicrosomes
dc.subjectMyocardial Ischemia
dc.subjectMyocardial Reperfusion
dc.subjectPhenylephrine
dc.subjectRats
dc.subjectRats, Wistar
dc.subjectReceptors, Adrenergic, alpha-1
dc.subjectReceptors, Cytoplasmic and Nuclear
dc.subjectSarcoplasmic Reticulum
dc.subjectAnimalia
dc.titleEffects of ischaemia, reperfusion and α1-adrenergic receptor stimulation on the inositoltrisphosphate receptor population in rat heart atria and ventricles
dc.typeArticle
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