Acute Caloric Restriction is Cardioprotective in Adult Rats

Abstract

Reduced coronary perfusion in acute coronary syndrome causes myocardial ischemia. Also the effect of reactive oxygen species (ROS) induced ischemia‐reperfusion injury contributes to myocardial lesion. ROS generation in hypoxia is modulated by the redox state. Fasting before exposure to ischemia should increase ketogenesis that consumes reduced coenzymes and consequently reduces free radical damage.We investigated whether the 3‐day fasting affects production of ROS, incidence of ventricular arrhythmias during ischemia/reperfusion and myocardial infarction size.We analyzed production of the lipid peroxidation end products (LFP) in the heart tissue. Open‐chest rats were subjected to 20‐min LAD coronary artery occlusion followed by reperfusion. A single‐lead ECG was recorded and arrhythmias were assessed. The infarction size in excised hearts was determined by triphenyltetrazolium chloride staining and it was normalized to area at risk (IS/AR).Three day fasting reduced LFP production in heart tissue. During early reperfusion the number of premature ventricular complexes was reduced in fasting rats compared to controls, as well as ventricular tachycardia duration. In fasting rats the IS/AR reached 48.5 ± 3.3 % while in controls it was 74.3 ± 2.2 %, p<0.005.Acute caloric restriction limits free radical damage in heart, reperfusion ventricular arrhythmias and myocardial infarction size in rats.Supported by GAUK 60009/2009 and MSMT 1M 0510.