title: Role of the dialyzer membrane on the overall phosphate kinetics during hemodialysis.
abstract: OBJECTIVE
  We investigated the potential role of the membrane type on phosphate kinetics.
  
  
  METHODS
  Six patients on dialysis (HD) were studied using modified cellulose (Hemophan), ethylene-vinyl alcohol (EVAL) and polyacrylonitrile (PAN). Total (TPR), extracellular (EPR) and intracellular (IPR) phosphate removal and effective dialyzer phosphate clearance (K(d)) were determined by the DDQ method. The intercompartment transfer coefficient (K(C)) was calculated using a mathematical model. Erythrocyte phosphate (P(ERY)) and 2,3-biphosphoglycerate (2,3-BPG) concentrations were determined before and after HD.
  
  
  RESULTS
  TPR was 1.2+/-0.4, 1.10+/-0.4 and 1.09+/-0.4 g with Hemophan, EVAL and PAN, respectively (p=n.s.). EPR and IPR were independent of membrane type. There was no difference in K(C) between membranes (321+/-70, 338+/-92 and 341+/-83 ml/min, respectively). The P(ERY) and 2,3--BPG remained statistically insignificant for all membranes.
  
  
  CONCLUSIONS
  Our results show that the type of membrane does not influence the kinetics of phosphate during dialysis, neither in the transfer from plasma to dialysate nor from the intra- to the extracellular compartment.
authors.affiliation: Department of Nephrology, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: Konstantinos P
authors.initials: KP
authors.lastname: Katopodis
authors.forename: Anna
authors.initials: A
authors.lastname: Chala
authors.forename: Elli
authors.initials: E
authors.lastname: Koliousi
authors.forename: Lamprini
authors.initials: L
authors.lastname: Takouli
authors.forename: Rigas
authors.initials: R
authors.lastname: Kalaitzidis
authors.forename: Joanna
authors.initials: J
authors.lastname: Theodorou
authors.forename: Kostas C
authors.initials: KC
authors.lastname: Siamopoulos
mesh_terms: D000180:Acrylic Resins; D000328:Adult; D000368:Aged; D002482:Cellulose / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D010710:Phosphates / Q000097:blood* / Q000302:isolation & purification; D011145:Polyvinyls; D006435:Renal Dialysis / Q000295:instrumentation*
chemical_list: D000180:Acrylic Resins; D008567:Membranes, Artificial; D010710:Phosphates; D011145:Polyvinyls; C054645:Hemophan; C010504:polyacrylonitrile; C020320:ethylene-vinyl alcohol copolymer; D002482:Cellulose