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Myocardial susceptibility to ischaemia/reperfusion in obesity : a re-evaluation of the effects of age

dc.contributor.authorWebster, I.en_ZA
dc.contributor.authorSalie, R.en_ZA
dc.contributor.authorMarais, E.en_ZA
dc.contributor.authorFan, W. J.en_ZA
dc.contributor.authorMaarman, G.en_ZA
dc.contributor.authorHuisamen, B.en_ZA
dc.contributor.authorLochner, A.en_ZA
dc.date.accessioned2017-03-17T10:13:04Z
dc.date.available2017-03-17T10:13:04Z
dc.date.issued2017-03-17
dc.identifier.citationWebster, I., et al. 2017. Myocardial susceptibility to ischaemia/reperfusion in obesity : a re-evaluation of the effects of age. BMC Physiology, 17:3, doi:10.1186/s12899-017-0030-y
dc.identifier.issn1472-6793 (online)
dc.identifier.otherdoi:10.1186/s12899-017-0030-y
dc.identifier.urihttp://hdl.handle.net/10019.1/100701
dc.descriptionCITATION: Webster, I., et al. 2017. Myocardial susceptibility to ischaemia/reperfusion in obesity : a re-evaluation of the effects of age. BMC Physiology, 17:3, doi:10.1186/s12899-017-0030-y.
dc.descriptionThe original publication is available at https://bmcphysiol.biomedcentral.com
dc.description.abstractBackground Reports on the effect of age and obesity on myocardial ischaemia/reperfusion (I/R) injury and ischaemic preconditioning are contradictory. The aim of this study was to re-evaluate the effects of age and diet-induced obesity (DIO) on myocardial I/R injury and preconditioning potential. Methods Four groups of Wistar male rats were used: age-matched controls (AMC) receiving standard rat chow for (i) 16 weeks and (ii) 16 months respectively; DIO rats receiving a sucrose-supplemented diet for (iii) 16 weeks and (iv) 16 months respectively. The ages of groups (i) and (iii) were 22 weeks (“young”) and groups (ii) and (iv) 17 months (“middle-aged”) at time of experimentation. Isolated perfused working hearts were subjected to 35 min regional ischaemia/1 h reperfusion. Endpoints were infarct size (tetrazolium staining) and functional recovery. Hearts were preconditioned by 3 × 5 min ischaemia/5 min reperfusion. Results were processed using GraphPad Prism statistical software. Results Age did not affect baseline heart function before induction of ischaemia and I/R damage as indicated by infarct size and similar values were obtained in hearts from both age groups. Age also had no effect on functional recovery of hearts during reperfusion after regional ischaemia in AMC rats, but cardiac output during reperfusion was better in hearts from middle-aged than young DIO rats. The diet reduced infarct size in hearts from young rats (% of area at risk: AMC: 32.4 ± 3.6; DIO: 20.7 ± 2.9, p < 0.05), with no differences in hearts from middle-aged rats (AMC: 24.6 ± 4.6; DIO: 28.3 ± 13.5, p = NS). Compared to their respective AMC, diet-induced obesity had no significant effect on functional recovery of hearts from both age groups after exposure to regional ischaemia. When exposed to the more severe stress of global ischaemia, the functional recovery potential of middle-aged DIO rats appeared to be impeded compared to hearts of young DIO rats, while age had no effect on the functional recovery of AMC hearts. Preconditioning reduced infarct size in hearts from young control rats and both middle-aged groups, but not from young DIO rats. Age had a significant effect on functional recovery in preconditioning: it was improved in hearts from young control and DIO rats, but depressed in both middle-aged groups. Conclusions The data showed that middle-age and obesity had no effect on baseline myocardial function and did not increase susceptibility to I/R damage upon exposure to regional ischaemia. On the contrary, obesity reduced I/R damage in young rats. Preconditioned aging hearts showed a decreased infarct size, but a reduction in functional recovery.
dc.description.urihttps://bmcphysiol.biomedcentral.com/articles/10.1186/s12899-017-0030-y
dc.format.extent13 pages
dc.language.isoen_ZA
dc.publisherBioMed Central
dc.titleMyocardial susceptibility to ischaemia/reperfusion in obesity : a re-evaluation of the effects of ageen_ZA
dc.typeArticleen_ZA
dc.date.updated2017-03-17T07:02:30Z
dc.description.versionPublisher's version
dc.rights.holderAuthor retains copyright


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