DETERMINATION OF [C-14] GLUTAMINE SPECIFIC ACTIVITY IN PLASMA

Glutamine is a key amino acid participating in various metabolic pathways. Study of the physiology of its carbon skeleton has been hampered by lack of a simple and precise method to measure its [C-14] specific activity in plasma. The present report describes an automated, sensitive and specific method to determine plasma [C-14] glutamine specific activity which can be used to measure glutamine carbon turnover and substrate-product interactions in vivo. An orto-phtalaldehyde derivative is analysed on a reverse phase column by UV detection. With this procedure mu Mol amounts of glutamine and other plasma compounds can be assayed for [C-14] specific activity. The method is sufficiently fast (25 samples in 24 hrs) and reproducible (CV<5.5%) for accurate measurements in a large volume of samples.