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

• Published in: BMC physiology 2017-03, Vol.17 (1), p.3-3, Article 3
• Main Authors: Webster, I, Salie, R, Marais, E, Fan, W-J, Maarman, G, Huisamen, B, Lochner, A
• Format: Article
• Language: English
• Subjects: Aging; AMP-activated protein kinase; Angiogenesis; Animal models; Animals; Cardiac conditioning; Cardiac muscle; Cardiovascular diseases; Cardiovascular system; Cell death; Coronary artery; Cyclosporins; Disease Models, Animal; Disease Susceptibility; Heart diseases; Hyperphagia; Insulin resistance; Ischemic Preconditioning, Myocardial - methods; Kinases; Life span; Male; Membrane permeability; Myocardial Infarction - metabolism; Myocardial Reperfusion Injury - complications; Myocardial Reperfusion Injury - metabolism; Myocardium - metabolism; Obesity; Obesity - complications; Obesity - metabolism; pH effects; Protein kinase; Rats, Wistar; Recovery of function; Rodents; Signal transduction; Temperature effects; Tumors; Vascular endothelial growth factor
• ISSN: 1472-6793; 1472-6793
• DOI: 10.1186/s12899-017-0030-y

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. 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. 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