Palmitate and stearate kinetics in the rat during sepsis and trauma

Kinetics of plasma free palmitate and stearate were measured in control and septic-traumatized rats to determine the contribution plasma free fatty acids make to increased resting energy expenditure. Measurements were made at 24 hr after insult using a primed, 4-hr continuous infusion of selected (1-14C) fatty acid. The plasma concentration of palmitate was increased and stearate was decreased in sepsis-trauma rats compared to plasma concentrations in healthy control rats. Fatty acid turnover rates during sepsis-trauma were changed from control turnover rates in the same direction as plasma concentrations. Oxidation rates for palmitate and stearate at 24 hr after induction of sepsis-trauma were not different from oxidation rates in control rats. Plasma free fatty acids were concluded not to exhibit increased oxidation after sepsis-trauma and not to contribute extra energy during hypercatabolism. This finding contrasts with glucose and amino acids which have an increased oxidation rate during hypercatabolism.