title: Branched-chain keto-acids and pyruvate in blood: measurement by HPLC with fluorimetric detection and changes in older subjects.
abstract: BACKGROUND
  Measurement of keto-acids is important in various clinical situations. The aim of the present work was to develop a rapid HPLC method for the determination of keto-acids in human serum and to assess the concentrations of these acids in young adults and institutionalized elderly adults. This method was applied to the determination of blood keto-acid concentrations of young adults and institutionalized elderly people, divided into age groups
  
  
  METHODS
  Four keto-acids (alpha-ketoisocaproate, alpha-ketoisovalerate, alpha-keto-beta-methylvalerate, and pyruvate) were derivatized with o-phenylenediamine to give fluorescent derivatives. After the sample preparation step (75 min to prepare 20 samples), the derivatives were separated chromatographically on a reversed-phase column using a binary gradient.
  
  
  RESULTS
  The fluorometric detection of the four keto-acids was rapid, <12 min. The method is repeatable and reproducible: the CVs were <6% and <11%, respectively, for each of the keto-acids. We found no significant difference between males and females. Concentrations of the branched-chain keto-acids decreased after age 60 years, especially alpha-ketoisocaproate, which decreased approximately 40%.
  
  
  CONCLUSIONS
  The proposed method allows rapid and reliable measurement of keto-acids. The data demonstrate that changes in branched-chain keto-acids concentrations in serum occur with age.
authors.affiliation: Biochem Laboratory, Emile Roux Hospital, Limeil-Brévannes, France.
authors.forename: K
authors.initials: K
authors.lastname: Pailla
authors.forename: F
authors.initials: F
authors.lastname: Blonde-Cynober
authors.forename: C
authors.initials: C
authors.lastname: Aussel
authors.forename: J P
authors.initials: JP
authors.lastname: De Bandt
authors.forename: L
authors.initials: L
authors.lastname: Cynober
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005470:Fluorometry; D006761:Hospitals; D006801:Humans; D007651:Keto Acids / Q000097:blood* / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D019289:Pyruvic Acid / Q000097:blood*; D011810:Quinoxalines / Q000737:chemistry
chemical_list: D007651:Keto Acids; D011810:Quinoxalines; D019289:Pyruvic Acid