Glutamine balance in metabolic acidosis as studied with the artificial kidney

Abstract

The relation between hepatic glutamine production and extrahepatic glutamine extraction was studied in the dog by hemodialysis of arterial blood with an artificial kidney. An excellent experimental metabolic acidosis can be produced this way by dialyzing bicarbonate out of the circulation. There is less change in renal blood flow and no significant change in hepatic blood flow. Arterial pH and [HCO3] fall, urinary pH decreases, and ammonia excretion increases; there is a rise in renal glutamine extraction and hepatic glutamine production. These last 2 functions show a highly significant correlation. If glutamine is removed by dialysis without an acidosis, hepatic glutamine production increases, but the correlation is not as great. Thus both acidosis and glutamine extraction play a role in setting the rate at which the liver adds glutamine to the blood.