Response to glucose and lipid infusions in sepsis: a kinetic analysis

The kinetics and oxidation of glucose and free fatty acid (FFA) metabolism were assessed in control and Escherichia coli septicemic dogs by using primed, constant infusions of U-14C-glucose and 1,2, 13C-palmitic acid. In the controls, the infusion of glucose suppressed endogenous glucose production completely, whereas, in the septic dogs, only a 30% suppression of glucose production occurred. The ability of the septic dogs to oxidize endogenous or exogenous glucose was decreased significantly. The basal rate of appearance of FFA was significantly higher in the septic dogs, but their ability to oxidize FFA was comparable to that of the control dogs; therefore, the basal rate of FFA oxidation was higher in the septic dogs. These studies indicate that septic dogs have a decreased capacity to oxidize glucose, but that they retain their ability to oxidize long-chain fatty acids. Because the rate of lipolysis was increased in sepsis, lipid was the predominate energy substrate in this septic model.