Measurement of branched-chain ketoacids in plasma by high-performance liquid chromatography

✍ Scribed by Mackenzie Walser; Louis M. Swain; Valerie Alexander

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 408 KB
• Volume: 164
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(87)90494-5

✦ Synopsis

Branched-chain ketoacids were isolated from plasma or serum samples by acidification, passage through a cationic exchange resin, ether extraction, and extraction of the ether layer with phosphate buffer. The recovery of 2-[ l-14C]ketoisocaproate taken through these procedures averaged 95 + 3%. Branched-chain ketoacids were measured by high-performance liquid chromatography using a single mobile phase (sodium phosphate:acetonitrile). In normal human subjects, mean + SD fasting levels of 2-ketoisocaproate, 2-keto-3-methylvalerate, and 2-ketoisovalerate were 29 f 8, 18 f 4, and 12 f 3 pM, respectively. In normal rats, slightly different results were found: 24 f 10, 19 + 7 and 17 + 6 PM, respectively. In both species, levels of each ketoacid expressed as fractions of total branched-chain ketoacids were much less variable.