Role of extra-splanchnic organs in the metabolic response to sepsis: effect of insulin.

The effect of sterile inflammation and sepsis on the release of lactate and amino acids by peripheral tissues was investigated in rats by removing the splanchnic organs (liver + small intestines) from the circulation and monitoring changes in blood metabolites over 30 min. Functional hepatectomy was performed in rats 5-7 days following the intraperitoneal introduction of a fecal-agar pellet (sterile vs. Bacteroides fragilis + E. coli). Lactate was significantly (P less than .05) increased in each of the conditions following hepatectomy but was raised to a significantly greater extent in sepsis (P less than .05). A similar response was observed for glutamine while alanine was only significantly (P less than .05) increased in sepsis following hepatectomy. Branched chain amino acids (BCAA) showed differential changes in sepsis compared to control. In control and sterile inflammation, functional hepatectomy was associated with significant decreases (P less than .05) in BCAA. In sepsis, BCAA were not decreased following hepatectomy and were significantly (P less than .05) elevated relative to control or sterile inflammation. Phenylalanine concentrations were not altered in control or sterile inflammation but were significantly elevated in sepsis (P less than .05). Insulin attenuated the accumulation of lactate and amino acids in fed control animals, following functional hepatectomy. However, in septic animals, insulin failed to prevent the rise in plasma lactate following hepatectomy.