[Changes in plasma free amino acid concentrations in rats during sepsis].

OBJECTIVE

To explore the relationship between plasma free amino acid concentrations and skeletal muscle proteolysis in rats during sepsis.

METHODS

An animal model of sepsis in rats was established by administering endotoxin into the peritoneal cavity. The plasma concentrations of free amino acid, ALT, AST, cortisol, TNF-alpha and IL-6 were determined. The rats were randomly divided into normal control, 2, 6, 12 and 24 h groups after administration of endotoxin(8 rats for each group).

RESULTS

The total plasma free amino acids concentrations fluctuate within normal range within 24 h after administration of endotoxin. A marked decrease in BCAA (branch-chainamino acid) was observed at 2, 6 and 12 h after administration of endotoxin, but aromatic amino acids (AAA) increased in varying degrees. BCAA/AAA was lower at 2 h and 6 h as compared with that of the normal control, while Phe/Tyr increased obviously at every time point. Lys, Sar, Cys and P-Ser showed no significant changes within 24 h after the administration of endotoxin. Thr, Glu, Orn, His, 3-MH and Ala increased during sepsis, and other amino acids more or less decreased. Plasma concentrations of ALT, AST, cortisol, TNF-alpha and IL-6 obviously increased within 24 h after the administration of endotoxin(P < 0.01). Cortisol peaked at 6 h and IL-6 peaked at 12 h, while TNF-alpha at 2 h.

CONCLUSION

The results suggested that metabolic disorder of plasma free amino acids during sepsis is due to enhancement of skeletal muscle proteolysis and liver overloading.