Renal glucose production in the intact dog.

ROSE, DAVID M., JOSEPH DISALVO, AND SULAMITA BALAGURABARUCH. Renal glucose production in the intact dog. Am. J. Physiol. 218(6): 1676-1681. 1970.-Renal glucose production was studied in anesthetized fasting (18 hr) dogs, in various states of acid-base balance, by two procedures: a) by measuring the difference of glucose concentration in renal venous and arterial plasma, using the standard glucose oxidase method; b) by measuring simultaneously the rates of renal release of 14C-labeled glucose during renal intra-arterial infusion of 14C-labeled a-ketoglutaric acid, malic acid, or glutamine. No net renal glucose production was detected by chemical means in the normal state, nor in chronic metabolic acidosis, acute metabolic alkalosis, and acute respiratory acidosis or alkalosis. In contrast, in all cases renal gluconeogenesis was detected from the appearance of 14C-labeled glucose in renal venous blood during renal intra-arterial infusion of 14C-labeled precursor. With this procedure, renal gluconeogenesis was detected even in the instances in which there was net extraction of glucose from arterial blood. Acute changes of acid-base balance altered the rates of renal release of 14C-labeled glucose but did not affect renal arterio-venous concentrations measured chemically. This study inclicatcs that renal gluconeogenesis is a process occurring continuously at extremely low rates which fail detection by chemical means and that its contribution to the economy of the body is negligible. If changes in rates of renal gluconeogenesis occur during changes of acid-base balance, as suggested by the isotopic measurements, their magnitucle is below the sensitivity of the standard glucose oxidase method.