The effect of L-ornithine hydrochloride ingestion on performance during incremental exhaustive ergometer bicycle exercise and ammonia metabolism during and after exercise.
OBJECTIVE
L-Ornithine has an important role in ammonia metabolism via the urea cycle. This study aimed to examine the effect of L-ornithine hydrochloride ingestion on performance during incremental exhaustive ergometer bicycle exercise and ammonia metabolism during and after exercise.


METHODS
In all, 14 healthy young adults (age: 22.2±1.0 years, height: 173.5±4.6 cm, body mass: 72.5±12.5 kg) who trained regularly conducted incremental exhaustive ergometer bicycle exercises after -ornithine hydrochloride supplementation (0.1 g/kg, body mass) and placebo conditions with a cross-over design. The exercise time (sec) of the incremental ergometer exercise, exercise intensity at exhaustion (watt), maximal oxygen uptake (ml per kg per min), maximal heart rate (beats per min) and the following serum parameters were measured before ingestion, 1 h after ingestion, just after exhaustion and 15 min after exhaustion: ornithine, ammonia, urea, lactic acid and glutamate. All indices on maximal aerobic capacity showed insignificant differences between both the conditions.


RESULTS
Plasma ammonia concentrations just after exhaustion and at 15 min after exhaustion were significantly more with ornithine ingestion than with placebo. Plasma glutamate concentrations were significantly higher after exhaustion with ornithine ingestion than with placebo.


CONCLUSIONS
It was suggested that, although the ingestion of L-ornithine hydrochloride before the exercise cannot be expected to improve performance, it does increase the ability to buffer ammonia, both during and after exercise.
Demura
S
S
Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Japan.
Yamada
T
T
Yamaji
S
S
Komatsu
M
M
Morishita
K
K
D000641:Ammonia / Q000097:blood / Q000378:metabolism; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D018698:Glutamic Acid / Q000097:blood; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018763:Muscle Fatigue; D009952:Ornithine / Q000008:administration & dosage* / Q000097:blood; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology*; D013997:Time Factors; D014508:Urea / Q000097:blood; D055815:Young Adult
D019344:Lactic Acid; D018698:Glutamic Acid; D000641:Ammonia; D014508:Urea; D009952:Ornithine