Glucose and lactate kinetics in guinea pigs following Escherichia coli endotoxin administration

Glucose and lactate turnovers were evaluated during the early stages (first three hours) of endotoxin-induced shock in unanesthetized male guinea pigs following the intravenous (IV) administration of 0.1 mg of Escherichia coli endotoxin. Rate of appearance (Ra), rate of disappearance (Rd), and metabolic clearance rate (MCR) of glucose and lactate were determined by the primed-constant infusion of [6-(3)H]-glucose and NA L(+)[U-14C]-lactate. Arterial glucose concentration was moderately elevated, and the Ra and Rd of glucose were increased significantly following endotoxin administration, while the slight increase in MCR was not statistically significant. Arterial lactate concentration was markedly increased and the Ra and Rd of lactate were significantly elevated. The percentage of [14C]-glucose derived from [14C]-lactate increased from 19% (control) to above 50% following endotoxin. From these data we found no evidence of impaired peripheral extraction of glucose. The increased glucose Ra and the higher percentage of [14C]-glucose being derived from [14C]-lactate suggest increased gluconeogenesis during the early stages following endotoxin administration.