One-compartment model for amino acids and other biological molecules in peritoneal dialysis
de la Motte, S.; Plum, J.; Passlick-Deetjen, J.; Grabensee, B.
International Journal of Clinical Pharmacology and Therapeutics 40(2): 60-68
2002
ISSN/ISBN: 0946-1965 PMID: 11862974 Document Number: 543744
Objectives: Investigation of the main factors determining the concentration-time course of amino acids and biological molecules in serum and dialysates. Methods: In a randomized, 3-period crossover study, 11 patients were treated once with each of 3 peritoneal dialysis solutions, 1 containing amino acids and bicarbonate, 1 containing glucose and bicarbonate and 1 containing glucose and lactate. Nineteen amino acids, 3 proteins, 2 metabolites and 2 ions were measured in serum and dialysate. A standard compartment model was fitted to the data. Results: The amino acids differed significantly in their kinetic characteristics (p<0.001), mainly volume of distribution and elimination rate. Differences in absorption were small compared to the interpatient variation. The average transport rate from serum to dialysate was 0.50-1.14 h-1, from dialysate to serum 0.33-0.41 h-1, for elimination from the central compartment 0.35 to 2.27 h-1, for volume of distribution 0.29 to 0.83 l/kg, for serum protein binding 19-47%, for amount in tissue 82-95%, for endogenous metabolic rate 16-151 mumolXkg-1Xh-1. The volume of distribution correlated with the R group (polar positive