Role of Fructose as a Potent Antiarrhythmic and Anti-infarct agent in Isolated Rat Heart

In the current study, effects of acute short term administration of fructose on cardiac arrhythmias and myocardial infarction size following ischemia/reperfusion were investigated in isolated rat heart. The hearts were subjected to 30 min zero flow global ischemia followed by 120 min reperfusion. In the control group, the hearts were perfused by normal drug free Krebs-Henseleit (K/H) solution throughout the experiments, while in the treated groups (2-4), they were perfused with fructose containing K/H solution at 12, 24 and 48 mM concentrations during stabilization and reperfusion time, respectively. Cardiac arrhythmias were determined based on the Lambeth conventions and the infarct size was measured by computerized planimetry. Myocardial infarction size was 22 ± 3% in the control group, however administration of fructose (12, 24 and 48 mM) reduced it to 15 ± 3 (P<0.05), 7±2 (P<0.001) and 4 ± 2% (P<0.001), respectively. A direct linear correlation between fructose concentrations and infarction size reduction was observed (R(2)=0.970). In addition, total number of ventricular ectopic beats were significantly decreased by all used concentrations of fructose (P<0.01 for group 2, P<0.001 for groups 3 and 4, respectively). Fructose also produced significant decrease in the number, incidence and duration of ventricular tachycardia compared to the control (P<0.05). The data showed that acute short term administration of fructose can protect isolated rat heart against ischemia/reperfusion injuries as reduction of infarct size and cardiac arrhythmias. Alterations in glycogen storage and/or glycolytic efficiency may probably involve in these cardioprotective effects. Also it is possible that fructose can act as a pharmacological preconditioning agent.