Metabolism of blood glucose by the intact functioning kidney of the dog.

The CO2 produced in the metabolism of blood glucose by the kidney has been measured by the i.v. infusion 14C-UL-D-glucose as a tracer. A small fraction of circulating 14C-glucose is converted to labeled lactate in extrarenal tissues, returned to, extracted by and metabolized to CO2 in the kidney. Correcting the apparent 14CO2 produced in the kidney from glucose for the 14CO2 produced from lactate yields that produced directly from glucose. Differences in production of CO2 from glucose in chronic metabolic acidosis and alkalosis are small and probably are not significant. If so, somewhat less than one-quarter of the total metabolism of the intact functioning kidney is supported by blood glucose. These measurements have been made at normal endogenous blood concentrations of glucose.