Beneficial effects of L-leucine and L-valine on arrhythmias, hemodynamics and myocardial morphology in rats

Branched chain amino acids (BCAA) have been shown to have a general protective effect on the heart in different animal models as well as in humans. However, so far no attempt has been made to specifically elucidate their influence on arrhythmias. Our study was performed to evaluate whether an infusion of either L-leucine or L-valine in a dose of 1 mg kg(-1) h(-1) 10 min before a 7-min period of left anterior descending artery occlusion followed by 15 min of reperfusion, had an effect on arrhythmias measured during the reperfusion phase in the ischemia- and reperfusion-induced arrhythmias model in rats in vivo. The effect of the infusion of these substances on mean arterial blood pressure was monitored throughout the experiment. Both of the tested amino acids exhibited significant antiarrhythmic properties. L-Leucine reduced the duration of ventricular fibrillation (P < 0.05) and L-valine decreased the duration of ventricular fibrillation (P < 0.001) and ventricular tachycardia (P < 0.05). The two amino acids were generally hypotensive. L-Valine lowered blood pressure in all phases of the experiment (P < 0.05) while L-leucine lowered this parameter mainly towards the end of occlusion and reperfusion (P < 0.05). In addition, 30 min infusion of the amino acids in the used dose did not produce any apparent adverse histological changes that were remarkably different from control. In summary, the results of our study suggest that L-leucine and L-valine in the dose that was used attenuates arrhythmias and are hypotensive in their influence. Our findings lend support to the many ongoing investigations into the benefit of the application of L-leucine and L-valine in cardiology like their addition to cardioplegic solutions. (C) 2011 Elsevier Ltd. All rights reserved.