Paired measurements were obtained from each patient during full nutritional support, but with and without intravenous exogenous glutamine supplementation. Nutri tional support consisted www.selleckchem.com/products/crenolanib-cp-868596.html of parenteral nutrition only or a combination of enteral and parenteral nutrition. The nutritional target was 20 kcal kg 24 h or energy expenditure as measured by indirect calorimetry. Extra glutamine was given by a constant intravenous infusion of 0. 28 g glutamine kg body weight during 20 h, given as an infusion of L alanyl L glutamine, 200 mg mL. Each measurement period included a bolus injection of 1 13C glutamine and ring 2H5 phenylalanine, followed by frequent plasma sampling during 90 minutes. The doses were chosen to give sufficient increments and decay curves of the isotopic labels without any major influence on the plasma concentrations of glutamine and phenylalanine, respect ively.

The decay Inhibitors,Modulators,Libraries curves allow for calculations of the Ra for glutamine and for phenylalanine by dividing the bolus injection by the area under the curve up to 90 minutes for the tracer analyses in the blood by a single pool model, In which Dose is the amount of the tracer injected and AUC is the area under the curve of the APE versus time. The exogenous given glutamine and phenylalanine from the dipeptide and nutrition were subtracted from the Ra to give estimates of the endogenous glutamine production, and of the endogenous phenylalanine production. As there is no endogenous Inhibitors,Modulators,Libraries de novo synthesis of phenylalanine, the latter gives an estimate of whole body protein degrad ation, which then enables a calculation of the fractions of endogenously produced glutamine that Inhibitors,Modulators,Libraries originates from protein breakdown and from de novo synthesis.

For this calculation we assumed whole body protein contents of glutamine and phenylalanine of 7. 0 and 4. 2%, respectively. Blood samples for analyses were drawn from an arterial Inhibitors,Modulators,Libraries line according to the protocol in Figure 1. To reduce the amount Inhibitors,Modulators,Libraries of blood needed for the two measurements the waste taken from the catheter before obtaining the real sample was given back to the patient in another intraven ous catheter. Samples in ethylenediaminetetraacetic acid tubes were immediately put on ice, 17-DMAG Phase 2 and centri fuged in a cool centrifuge within 30 minutes to obtain plasma, which was stored at ?80 C pending analysis. Plasma samples were analyzed for glutamine and phenylalanine enrichments and concentrations using gas chromatography mass spectrometry mea surements as described before. In short, plasma was deproteinized using methanol. Ammonium formate was added at this step to prevent conversion of glutamine to glutamate.