Human and animal studies have demonstrated that glutamine catabolism exceeds glutamine synthesis in burn patients, resulting in a glutamine-depleted status, which compromises liver function, including glutathione status, proline and arginine homeostasis and whole body protein balance (1). The purpose of this study is to directly quantify glutamine / glutamate kinetics in relation to glutamine / glutamate disposal and whole body amino acid balance, by using stable isotope tracers [1-13C, 15N]leucine and [15N2]urea.