Branched-chain keto-acids and pyruvate in blood: measurement by HPLC with fluorimetric detection and changes in older subjects.
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.
Pailla
K
K
Biochem Laboratory, Emile Roux Hospital, Limeil-Brévannes, France.
Blonde-Cynober
F
F
Aussel
C
C
De Bandt
J P
JP
Cynober
L
L
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
D007651:Keto Acids; D011810:Quinoxalines; D019289:Pyruvic Acid