title: Determination of pyrophosphate in renal calculi and urine by means of an enzymatic method.
abstract: An enzymatic method for the determination of pyrophosphate which has been applied to renal calculi is described. The method involves the preconcentration of pyrophosphate using anionic exchange resin and development of the enzymatic reactions with the pyrophosphate retained on the resin. The study of calculi treatment according to calculi composition is also reported. The pyrophosphate content was dependent on the calculi composition. The highest amount of pyrophosphate was found in hydroxyapatite calculi (of the order of 10 microg/g), struvite and oxalate calculi showed a lower amount (the order was 2.5 and 4.5 microg/g, respectively) and was not detected in uric acid and cystine stones. The method was also successfully applied to the determination of pyrophosphate in human urine. For urinary pyrophosphate determination, a modification based on a clean-up of urine using activated carbon has been proposed. Pyrophosphate in human urine was of the order of 4 mg l(-1).
authors.affiliation: Department of Chemistry, University of Balearic Islands, Campus de la UIB, Ctra. Valldemossa km 7.5, E 07071 Palma de Mallorca, Spain. joan.march@uib.es
authors.forename: J G
authors.initials: JG
authors.lastname: March
authors.forename: B M
authors.initials: BM
authors.lastname: Simonet
authors.forename: F
authors.initials: F
authors.lastname: Grases
mesh_terms: D000465:Algorithms; D003553:Cystine / Q000032:analysis; D011756:Diphosphates / Q000032:analysis* / Q000652:urine; D005634:Fructose-Bisphosphate Aldolase / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007669:Kidney Calculi / Q000737:chemistry* / Q000652:urine; D010070:Oxalates / Q000032:analysis / Q000652:urine; D012016:Reference Values; D013056:Spectrophotometry, Ultraviolet; D014527:Uric Acid / Q000032:analysis / Q000652:urine
chemical_list: D011756:Diphosphates; D007202:Indicators and Reagents; D010070:Oxalates; D014527:Uric Acid; D003553:Cystine; D005634:Fructose-Bisphosphate Aldolase