Effects of an amino acid dialysate on leucine metabolism in continuous ambulatory peritoneal dialysis patients.
BACKGROUND
Protein-energy malnutrition is frequent in continuous ambulatory peritoneal dialysis (CAPD) patients. The use of amino acids in the dialysate could improve the protein balance, especially if associated to a concomitant energy intake.


METHODS
A 1.1% amino acid solution for peritoneal dialysis was administered to CAPD patients over 30 minutes during concomitant absorption of 600 ml water (control study) or of a 600 kcal meal/600 ml. Leucine metabolism was studied using the combination of intravenous [2H3] and intraperitoneal [13C] leucine.


RESULTS
The rate of leucine appearance was stimulated by 56 and 53% (control and meal) at 45 minutes. The rates of leucine appearance and disappearance were lower from 180 to 300 minutes during the meal versus control study (P < 0.05). Proteolysis was unaffected during the control study and was inhibited by 25% during the meal study (P < 0.05). During the five-hour cycle dialysis with or without a meal, 80% of the leucine administered into the peritoneum was absorbed. Forty-one percent was retained in the splanchnic bed. Forty-three percent was used for protein synthesis, and 16% was oxidized.


CONCLUSIONS
This amino acids solution is efficaciously utilized for protein synthesis in CAPD patients with no effect on protein breakdown. The concomitant ingestion of a carbohydrate-lipid meal inhibits protein breakdown and reinforces a positive effect of the amino acids solution on protein balance.
Delarue
J
J
Laboratoire de Nutrition de Tours, Association Régionale dAide aux Urémiques du Center Ouest, Hôpital Neuro-cardiologique, Lyon, France. delarue@med.univ-tours.fr
Maingourd
C
C
Objois
M
M
Pinault
M
M
Cohen
R
R
Couet
C
C
Lamisse
F
F
D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D050260:Carbohydrate Metabolism; D005260:Female; D006801:Humans; D007930:Leucine / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D012119:Respiration
D000596:Amino Acids; D001786:Blood Glucose; D007930:Leucine