The Effect of L-citrulline Ingestion on ECG QT Interval and Autonomic Nervous System Activity

Abstract

The purpose of this study was to investigate the effect of L-citrulline ingestion on ECG QT interval. To accomplish this purpose, nine male subjects (age: 23.4Ϯ0.5 years, weight: 57.7Ϯ5.6 kg) participated, who had no history of cardiovascular or respiratory function disorders. Each subject performed two tests (L-citrulline and placebo ingestion) on a separate day. ECG was taken before, and 60 min and 90 min after L-citrulline ingestion. The heart-ratecorrected QT interval (QTc) decreased significantly 60 min ( pϭ0.0004) and 90 min (pϭ0.011) after L-citrulline ingestion. However, there were no significant changes after placebo ingestion. In addition, the interaction between L-citrulline ingestion and placebo was significant (two-way ANOVA: interaction, pϭ0.010). Our major finding was that L-citrulline ingestion decreases the QT interval in healthy subjects. This result suggests that transient L-citrulline ingestion may shorten the time required to complete myocardial depolarization and repolarization.

Oral nitrate and citrulline decrease blood pressure and increase vascular conductance in young adults: a potential therapy for heart failure

“…Interestingly, when the apparent reduction in R–R interval is taken into account the QRS interval is preserved across all interventions, suggesting that our observations were a direct result of the modest tachycardia caused by citrulline. These observations were in direct contrast to earlier studies showing a decrease in QTc interval (Kameda et al 2011 ) following acute consumption of citrulline. Whilst exploiting the same citrulline dose as used in our current experiment, these observations were made after acute consumption of citrulline (60 min) (Kameda et al 2011 ) whilst our experiment demonstrates the effects of chronic citrulline consumption.…”

“…Such changes may be responsible for the modest tachycardia we noted for subjects consuming citrulline. Similar observations were noted for previous experiments exploiting the same dose of citrulline measured after only 60 min, but no direct measure of HR was made during these experiments (Kameda et al 2011 ). Interestingly, the impact on sympathetic tone was modest as a challenge to strongly stimulate the sympathetic NS (a breath-hold) had no effect on the sympathovagal balance when compared with untreated subjects.…”

Citrulline in health and disease. Review on human studies

“…Electrophysiological mechanisms may also be important. A study in healthy individuals given CIT (3.2g 60-90 minutes before testing) demonstrated a reduction in QT interval on electrocardiography, indicative of a shortening of the time required to de/repolarize the myocardium (40) .…”

Effects of Oral L-Citrulline Supplementation on Lipoprotein Oxidation and Endothelial Dysfunction in Humans with Vasospastic Angina

“…A recent study demonstrated that oral supplementation with L-citrulline upregulates endothelial eNOS expression, causes dramatic regression in atheromatous lesions and plays an inhibitory role in the progression of atherosclerosis in animal models [ 13 , 14 ]. Moreover, we and others have revealed in clinical trials that L-citrulline supplementation functionally improves arterial stiffness [ 15 ], causes a reduction in the heart-rate corrected QT interval as a marker of sudden cardiac death [ 16 ], and decreases ankle blood pressure and carotid wave reflection [ 17 ]. L-Citrulline may thus be considered a useful ingredient for protecting against atherosclerotic coronary artery disease.…”