Effect of amino acid administration on uremic muscle metabolism: a 31P-spectroscopy study.
The effect of a six-month peritoneal amino acid administration on muscle metabolism at rest and during exercise was examined in 12 patients (4 control and 8 amino acid treated) on continuous ambulatory peritoneal dialysis. 31P-magnetic resonance spectroscopy was used to measure several high-energy phosphates (PCr, Pi) in resting muscle and during exercise and recovery. At rest, no significant changes were detected between the non-treated (control) and the amino acid treated (experimental) group. Before the administration of amino acids, the exercise-induced fall in [PCr], the increase in [ADP] and [Pi] and the pH were not significantly different in the control and experimental group. The initial rate of PCr recovery and the calculated maximal rate of ATP-synthesis (Qmax) for the control subjects was not significantly different at the onset and the end of the study. In the treated group, however, the fall in [PCr] and increase in [ADP] after exercise were significantly lower after than before treatment, while [Pi] and pH were identical. The initial rate of PCr recovery and Qmax were also significantly improved. These changes indicate an improved oxidative phosphorylation under the treatment and suggest that the impaired oxidative metabolism of the dialysis patients could be the result of their bad nutritional state.
De Bisschop
E
E
Biomedical MR Unit, Vrije Universiteit Brussel, Belgium.
Allein
S
S
Van der Niepen
P
P
Verbeelen
D
D
Luypaert
R
R
Osteaux
M
M
Malaisse
W
W
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000008:administration & dosage*; D015314:Dialysis Solutions; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D010531:Peritoneal Dialysis, Continuous Ambulatory; D010710:Phosphates / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D010759:Phosphorus Isotopes; D010766:Phosphorylation; D014511:Uremia / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism*
D000596:Amino Acids; D015314:Dialysis Solutions; D010710:Phosphates; D010759:Phosphorus Isotopes; D010725:Phosphocreatine; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate