title: Charge-affected transperitoneal movement of amino acids in CAPD.
abstract: Our objective was to investigate the influence of molecular charge on transperitoneal solute movement in continuous ambulatory peritoneal dialysis (CAPD). Tests of peritoneal equilibration were performed. Two liters of 2.27% or 2.5% glucose CAPD dialysate were infused and the dialysate samples were taken after 2 hr and 4 hr, and blood samples were obtained after 4-hr dwell time. Dialysate-to-plasma concentrations ratios (D/P) were calculated for creatinine (Cr) and three amino acids with almost the same molecular weight but quite different charges: glutamic acids (Glu: negatively charged), glutamine (Gln: near neutrally charged), and lysine (Lys: positively charged). The setting was a university hospital. There were 23 stable CAPD patients with a mean age of 56.6 +/- 9.5 years and a mean CAPD duration of 15.2 +/- 19.4 months. D/P ratio of Glu was much lower than those of Gln, Lys and Cr at both 2 hr and 4 hr (p < 0.01), and D/P of Lys was significantly lower than that of Gln (p < 0.01). There was no significant difference of D/P between Gln and Cr. The order of transperitoneal mobility among the three amino acids was Gln > Lys > Glu. Transperitoneal movement of solutes in CAPD is influenced by molecular charge, the movement of negatively charged solutes is most remarkably retarded in cases of amino acids.
authors.affiliation: Department of Nephrology, Tokyo Medical University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakao
authors.forename: M
authors.initials: M
authors.lastname: Ogura
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Okada
mesh_terms: D000328:Adult; D000368:Aged; D001202:Ascitic Fluid / Q000378:metabolism; D002199:Capillary Permeability / Q000502:physiology; D003404:Creatinine / Q000378:metabolism; D015314:Dialysis Solutions / Q000493:pharmacokinetics*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology* / Q000628:therapy; D008239:Lysine / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials / Q000502:physiology*; D008875:Middle Aged; D010537:Peritoneum / Q000503:physiopathology*
chemical_list: D015314:Dialysis Solutions; D005973:Glutamine; D018698:Glutamic Acid; D003404:Creatinine; D008239:Lysine