title: Enzymatic erythrocyte creatine determinations as an index for cell age.
abstract: Creatine concentration in red blood cells was determined after ammoniumsulfate precipitation on a clear hemoglobin-free filtrate with a new enzymatic assay making use of bacterial creatinase. The method described is more specific than Griffiths' method and can easily be mechanised and adapted for use in a routine laboratory using classical automated equipment. By contrast with Griffiths' method no significant interferences of amino acids and creatine-like molecules were found. Reference values for this method were 0.379 +/- 0.076 mmol/l. In patients with high turnover of erythrocytes, e.g. haemodialysis patients (0.529 +/- 0.122 mmol/l), and renal insufficiency patients (0.565 +/- 0.145 mmol/l), significantly increased creatine concentration in erythrocytes were observed. Low erythrocyte creatine concentrations were found in chronic ambulatory dialysis patients (0.311 +/- 0.042 mmol/l).
authors.affiliation: Department of Clinical Chemistry, Universitair Ziekenhuis, Gent, Belgium.
authors.forename: A M
authors.initials: AM
authors.lastname: Buysse
authors.forename: J R
authors.initials: JR
authors.lastname: Delanghe
authors.forename: M L
authors.initials: ML
authors.lastname: De Buyzere
authors.forename: I K
authors.initials: IK
authors.lastname: De Scheerder
authors.forename: A M
authors.initials: AM
authors.lastname: De Mol
authors.forename: L
authors.initials: L
authors.lastname: Noens
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000032:analysis; D003401:Creatine / Q000097:blood*; D004905:Erythrocyte Aging; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000032:analysis*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D014512:Ureohydrolases
chemical_list: D000596:Amino Acids; D014512:Ureohydrolases; C019944:creatinase; D003401:Creatine