Metabolism of non-protein energy-substrates in septic rats receiving parenteral nutrition.

The influences of sepsis on the metabolism of fatty acid and glucose in rats receiving parenteral nutrition were investigated. The caecum, with its blood supply, was ligated in 10 rats to produce peritonitis and sepsis (septic rats). Twelve rats (control rats) did not undergo this procedure. Five septic rats and six control rats received glucose as a sole nonprotein calorie (septic-glucose rats), and the remaining five septic rats (septic-lipid rats) and six control rats received the same parenteral solution for the first 44 hours, but 25% of the nonprotein calorie was replaced by 10% lipid emulsion for the last 24 hours. At the termination of the parenteral nutrition, 14C-linoleic acid or 14C-glucose was injected as a bolus in the tail vein, and their degradations to 14CO2 and incorporations into the endogenous fat were compared among the three groups. It was demonstrated that the sepsis accelerated the oxidation of fatty acid but did not affect that of glucose. Hepatic lipogenesis with both fatty acid and glucose was accelerated by an infusion of glucose under a septic condition, while it was inhibited by an infusion of lipid emulsion.