The effects of insulin and β-adrenergic stimulation on glucose transport, glut 4 and PKB activation in the myocardium of lean and obese non-insulin dependent diabetes mellitus rats

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dc.contributor.authorHuisamen B.
dc.contributor.authorVan Zyl M.
dc.contributor.authorKeyser A.
dc.contributor.authorLochner A.
dc.date.accessioned2011-05-15T16:00:00Z
dc.date.available2011-05-15T16:00:00Z
dc.date.issued2001
dc.description.abstractGlucose uptake, glut 4 translocation and activation of protein kinase B were measured in Langendorff perfused hearts from (i) Wistar control, (ii) lean, neonatal Streptozotocin induced (Stz) and (iii) Zucker (fa/fa) obese diabetic rats of 10-12 weeks old. Hearts were subjected to stimulation with insulin, isoproterenol (β-adrenergic agonist) or a combination of insulin and isoproterenol, during the perfusion protocol. Basal myocardial glucose uptake was impaired in both diabetic models, but could be stimulated significantly by insulin. In the Zucker rats, the time-course of insulin action was delayed. Insulin and β-stimulation of glucose uptake were not additive. Evaluation of sarcolemmal membranes from these hearts showed that the affinity of glut 4 was significantly lower in the Zucker but not in the Stz hearts while a reduced affinity found with a combination of insulin and β-stimulation in control hearts, was absent in both diabetic models. Total membrane lysates were analyzed for glut 4 expression while an intracellular component was generated to quantify translocation on stimulation as well as activity of protein kinase B (PKB). At this age, the neonatal Streptozotocin induced diabetic animals presented with more faulty regulation concerning adrenergic stimulated effects on elements of this signal transduction pathway while the Zucker fa/fa animals showed larger deviations in insulin stimulated effects. The overall response of the Zucker myocardium was poorer than that of the Stz group. No significant modulation of β-adrenergic signaling on insulin stimulated glucose uptake was found. The PI-3-kinase inhibitor wortmannin, could abolish glucose uptake as well as PKB activation elicited by both insulin and isoproterenol.
dc.description.versionArticle
dc.identifier.citationMolecular and Cellular Biochemistry
dc.identifier.citation223
dc.identifier.citation02-Jan
dc.identifier.issn3008177
dc.identifier.other10.1023/A:1017528402205
dc.identifier.urihttp://hdl.handle.net/10019.1/11478
dc.subjectglucose
dc.subjectglucose transporter
dc.subjectglucose transporter 4
dc.subjectinsulin
dc.subjectisoprenaline
dc.subjectprotein kinase B
dc.subjectstreptozocin
dc.subjectunclassified drug
dc.subjectwortmannin
dc.subjectage
dc.subjectanimal experiment
dc.subjectanimal model
dc.subjectanimal tissue
dc.subjectarticle
dc.subjectbeta adrenergic stimulation
dc.subjectcell lysate
dc.subjectclinical protocol
dc.subjectcontrolled study
dc.subjectenzyme activation
dc.subjectfemale
dc.subjectglucose transport
dc.subjectheart muscle
dc.subjectheart muscle fiber membrane
dc.subjectheart perfusion
dc.subjectlean body weight
dc.subjectmale
dc.subjectmodulation
dc.subjectnewborn
dc.subjectnon insulin dependent diabetes mellitus
dc.subjectnonhuman
dc.subjectobesity
dc.subjectrat
dc.subjectregulatory mechanism
dc.subjectsignal transduction
dc.subjectstreptozocin diabetes
dc.subjecttime
dc.subjectAdrenergic beta-Agonists
dc.subjectAnimals
dc.subjectDiabetes Mellitus
dc.subjectDiabetes Mellitus, Experimental
dc.subjectDiabetes Mellitus, Type 2
dc.subjectEnzyme Activation
dc.subjectGlucose
dc.subjectGlucose Transporter Type 4
dc.subjectHeart
dc.subjectInsulin
dc.subjectIsoproterenol
dc.subjectMonosaccharide Transport Proteins
dc.subjectMuscle Proteins
dc.subjectMyocardium
dc.subjectObesity
dc.subjectProtein Transport
dc.subjectProtein-Serine-Threonine Kinases
dc.subjectProto-Oncogene Proteins
dc.subjectProto-Oncogene Proteins c-akt
dc.subjectRats
dc.subjectRats, Wistar
dc.subjectRats, Zucker
dc.titleThe effects of insulin and β-adrenergic stimulation on glucose transport, glut 4 and PKB activation in the myocardium of lean and obese non-insulin dependent diabetes mellitus rats
dc.typeArticle
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