Effect of arginine, ornithine and citrulline supplementation upon performance and metabolism of trained rats

Abstract

During intense exercise there is an augmented production of ammonia and IMP in the exercised muscle that could be related to the establishment of peripheral fatigue. In order to prevent this accumulation, the urea cycle in the liver eliminates ammonia in the form of urea and the skeletal muscle buffers the increase of ammonia via transamination reactions. In the present study we evaluated the effect of arginine, citrulline and ornithine supplementation, intermediates of the urea cycle, on the performance of sedentary and swimming-trained rats submitted to a single bout of exhaustive exercise. We also measured the glycogen content of the soleus and gastrocnemius muscles and of the liver, as well as the plasma concentrations of ammonia, urea, glutamine, glucose and lactate. The results indicate that arginine, citrulline and ornithine supplementation increased the flux of substrate through the reaction catalysed by glutamine synthetase, leading to increased glutamine production after an exhaustive bout of exercise, and of the mechanism involved in ammonia buffering.

The effect of L-ornithine hydrochloride ingestion on performance during incremental exhaustive ergometer bicycle exercise and ammonia metabolism during and after exercise

“…Because the plasma glutamate concentration significantly increased an hour after the ingestion of L-ornithine hydrochloride and was significantly greater in the L-ornithine hydrochloride condition than that in the placebo condition immediately following and 15 min after exercise, the inhibition of ammonia concentration increase may be largely contributed to the ammonia buffering in the skeletal muscle. A difference between the results and the working hypothesis in this study was found also in the study by Meneguello et al (2003). They reported that, although a decrease in the plasma ammonia concentration and a reduction in fatigue were found, the plasma urea concentration also decreased during maximal exhaustive exercise after the ingestion of arginine, citrulline and ornithine, which are intermediates of the urea cycle, in rats.…”

Effects of Citrulline Supplementation on Fatigue and Exercise Performance in Mice

“…Several previous studies have examined the antifatigue effects of amino acids that are components of the urea cycle. Meneguello et al reported that supplementation with a mixture of citrulline, arginine, and ornithine suppressed the accumulation of blood ammonia after exercise and prolonged the time to exhaustion in a swimming task by about 60% ( 11 ). Although a single supplementation of arginine or ornithine suppressed the increase in the blood level of ammonia, any effect on exercise performance was obscure (12)(13)(14).…”

“…In a study using mice, Meneguello et al found that supplementation with a citrulline/arginine/ornithine mixture supressed the accumulation of blood ammonia after exercise and prolonged the time until exhaustion in a swimming task ( 11 ). Although arginine or ornithine supplementation is reported to suppress the accumulation of ammonia, few studies have examined whether this improves exercise performance in mice or humans (12)(13)(14).…”

Effect of Conclevan on Endurance Capacity in Mice

“…The concentrations of serum glucose, corticosterone, lactic acid, ammonia, and glutamine are known to serve as indicators of accumulated fatigue and stress caused by exercise. 12,[17][18][19] The analysis of these components in the blood samples collected after the last measurement of the swimming time at the sixth week of the administration showed decreases in the serum concentrations of glucose and glutamine, along with increases in the serum concentrations of corticosterone, lactic acid, and ammonia in the swimming control group compared to the non-swimming control group (Fig. 3).…”