Ammonia response to constant exercise: differences to the lactate response.
1. We evaluated the plasma ammonia response to constant exercise at different intensities. Ten healthy male volunteers were asked to perform constant exercise for 15 min at five different intensities: 80, 90, 100, 110 and 120% of their ventilatory threshold (VT). Blood concentrations of lactate, ammonia and hypoxanthine were measured during and after exercise. 2. The concentration of lactate increased continuously during exercise intensities equivalent to 100, 110 and 120% VT. Plasma ammonia began to increase at 6 min exercise and continued increasing during exercise at all five exercise intensities. Plasma hypoxanthine levels also increased continuously during exercise at all exercise intensities; however, they peaked at 5-10 min after exercise. The response of plasma ammonia and hypoxanthine increased with increasing intensities of exercise. 3. While the extent of the increase in lactate levels during exercise at 100, 110 and 120% VT was significantly higher than that at 80% VT, only the increase in ammonia and hypoxanthine levels at 120% VT were significantly higher than those at 80% VT. 4. In conclusion, the plasma ammonia response to constant exercise differed to the lactate and ammonia responses to short-term exhaustive exercise.
Ogino
K
K
First Department of Medicine, Faculty of Medicine, Tottori University, Yonago, Japan. ogino@grape.med.tottori-u.ac.jp
Kinugawa
T
T
Osaki
S
S
Kato
M
M
Endoh
A
A
Furuse
Y
Y
Uchida
K
K
Shimoyama
M
M
Igawa
O
O
Hisatome
I
I
Shigemasa
C
C
D000328:Adult; D000641:Ammonia / Q000097:blood*; D015308:Anaerobic Threshold / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019271:Hypoxanthine / Q000097:blood; D019344:Lactic Acid / Q000097:blood*; D008297:Male
D019271:Hypoxanthine; D019344:Lactic Acid; D000641:Ammonia