Epinephrine-induced increase in glucose turnover is diminished during sepsis

The responsiveness of septic rats to epinephrine-induced alterations in carbohydrate metabolism was studied. Nonlethal sepsis was produced by subcutaneous injections of live Escherichia coli over 18 hours in conscious catheterized rats. Glucose kinetics were assessed by IV infusion of [6-3H]-glucose. After two hours of tracer infusion, blood samples were taken for basal values. Thereafter, epinephrine was infused at 0, 0.05, 0.2, or 1.0 microgram/min/kg for an additional four hours. Compared with nonseptic rats, septic animals had increased basal values for glucose rate of appearance (Ra, 63%), glucose clearance (86%), and plasma lactate concentration (133%). Infusion of epinephrine resulted in dose-dependent increases in glucose Ra, as well as plasma glucose and lactate concentrations, and decreases in glucose clearance and muscle glycogen content. At each dose of epinephrine, the increases in response from basal of plasma glucose and glucose Ra in septic rats were 50% or less of that observed in nonseptic animals. There were no differences between septic and nonseptic rats in plasma lactate and glucose clearance responses from basal or in circulating levels of catecholamines achieved during the epinephrine infusion. The present results indicate that septic rats are less responsive than control animals to epinephrine-induced increases in glucose turnover.