Using routine blood chemistry results to estimate changes in plasma AA during experimental endotoxemia

Abstract

Plasma amino acids (AA) markedly change during infection, but they are rarely monitored during hospitalization. Arg, Glu, Ala, and the aromatic AA have important immunological functions. Young pigs (26.9±1.1 kg, n=9) were fitted with an indwelling jugular catheter for blood sampling. After a 2‐h feeding period, pigs were given 10 μg/kg BW of E. coli‐derived LPS i.v. Plasma AA and several blood metabolites (e.g., creatinine, urea N, protein, P, Ca, TG, HDL, glucose, lactate, etc.) were measured every 2 h for 12 h. Quadratic changes (P<0.04) in Pro, Arg, Tyr, Val, Leu, Asn, Ile, Met, Phe, Orn, and Trp were determined after LPS injection. Plasma total protein (PTP, r2=0.003 to 0.18) and urea N (BUN, r2=0.001 to 0.23) were poorly correlated to plasma AA levels during an LPS challenge. The use of multiple blood chemistry results better (P<0.01) accounted for plasma levels of Arg (R2=0.61), Ala (R2=0.80), Trp (R2=0.75), Phe (R2=0.77), Tyr (R2=0.67), Met (R2=0.62), Lys (R2=0.30), Leu (R2=0.71), and Val (R2=0.69) than PTP or BUN alone. These findings suggest that plasma AA could be estimated using various routine blood chemistry results. Funding: Virginia Agricultural Experiment Station.Grant Funding Source: Virginia Agricultural Experiment Station