Altered Dynamics in Splanchnic Amino Acid Extraction During Early Sepsis Recovery in Pigs: Whole Body Compared with Interorgan Balance Assessments

BACKGROUND: Establishing the metabolic fate of nutrients from food intake is crucial for interpreting the benefits of food interventions. Using stable isotopes labeled amino acids (AA) such as L-phenylalanine (Phe) during feeding allows for the determination of first-pass splanchnic extraction (SPE) on a whole-body level (WbSPE). The relationship between this measure and the total fraction of food-derived Phe retained by the splanchnic area has not been validated. OBJECTIVE: Therefore, we compared WbSPE with the enteral-derived Phe and actual PheSPE, measured by splanchnic-trans-organ fluxes in both healthy and early sepsis recovery states. METHODS: C]-Phe, were administered for 6 h. We collected arterial, portal, and hepatic venous blood and measured plasma enrichments and tracee concentrations by liquid chromatography-mass spectrometry (LC-MS/MS). Statistical analysis was performed using GraphPad Prism. Best-fit group means from the last 3 h were compared using an unpaired t-test. The data are presented as mean [95% confidence interval]. RESULTS: In the healthy control group, WbSPE was 38[16,61]% (P