Abstract
Originalsprog | Engelsk |
---|---|
Tidsskrift | American Journal of Physiology: Endocrinology and Metabolism |
Vol/bind | 259 |
Udgave nummer | 2 |
Sider (fra-til) | E170-E176 |
ISSN | 0193-1849 |
Status | Udgivet - 1990 |
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Ammonia metabolism during intense dynamic exercise and recovery in humans. / Graham, T; Bangsbo, Jens; Gollnick, PD; Juel, Carsten; Saltin, Bengt.
I: American Journal of Physiology: Endocrinology and Metabolism, Bind 259, Nr. 2, 1990, s. E170-E176.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review
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TY - JOUR
T1 - Ammonia metabolism during intense dynamic exercise and recovery in humans
AU - Graham, T
AU - Bangsbo, Jens
AU - Gollnick, PD
AU - Juel, Carsten
AU - Saltin, Bengt
PY - 1990
Y1 - 1990
N2 - This study examined the dynamics for ammonia (NH3) metabolism in human skeletal muscle during and after intense one-legged exercise. Subjects (n = 8) performed dynamic leg extensor exercise to exhaustion (3.2 min). MuscleNH3 release increased rapidly to a maximum of 314 +/- 42 mumol/min and declined immediately on cessation of exercise. Recovery was complete in approximately 20 min. Arterial [NH3] increased less rapidly and reached itsmaximum 2-3 min into recovery. These data demonstrate that NH3 clearance is more sensitive to the cessation of exercise than is NH3 release from skeletal muscle. Muscle [NH3] increased three to fourfold during exercise and represented 74 +/- 8% of the total net NH3 formation. Thus the change in muscle [NH3] alone underestimates the NH3 production. There was no evidence that the muscle-to-venous blood NH3 ratio shifts in accordance with the H+ data. Thus other factors must contribute to the NH3 release from active muscle. The total net NH3 formed corresponded with the intramuscular inosine 5'-monophosphate accumulation, suggesting that the NH3 was derived from AMP deamination. Changes in the known modulators of AMP deaminase (ATP, ADP, H+) were moderate, so the mechanisms initiating the deamination remain obscure.
AB - This study examined the dynamics for ammonia (NH3) metabolism in human skeletal muscle during and after intense one-legged exercise. Subjects (n = 8) performed dynamic leg extensor exercise to exhaustion (3.2 min). MuscleNH3 release increased rapidly to a maximum of 314 +/- 42 mumol/min and declined immediately on cessation of exercise. Recovery was complete in approximately 20 min. Arterial [NH3] increased less rapidly and reached itsmaximum 2-3 min into recovery. These data demonstrate that NH3 clearance is more sensitive to the cessation of exercise than is NH3 release from skeletal muscle. Muscle [NH3] increased three to fourfold during exercise and represented 74 +/- 8% of the total net NH3 formation. Thus the change in muscle [NH3] alone underestimates the NH3 production. There was no evidence that the muscle-to-venous blood NH3 ratio shifts in accordance with the H+ data. Thus other factors must contribute to the NH3 release from active muscle. The total net NH3 formed corresponded with the intramuscular inosine 5'-monophosphate accumulation, suggesting that the NH3 was derived from AMP deamination. Changes in the known modulators of AMP deaminase (ATP, ADP, H+) were moderate, so the mechanisms initiating the deamination remain obscure.
M3 - Journal article
VL - 259
SP - E170-E176
JO - American Journal of Physiology - Endocrinology and Metabolism
JF - American Journal of Physiology - Endocrinology and Metabolism
SN - 0193-1849
IS - 2
ER -