Development of an Intravenous Bile Acid Tolerance Test: Plasma Disappearance of Cholylglycine in Health

To develop an intravenous bile acid tolerance test that might be useful for detecting impaired liver function or liver injury, the plasma disappearance of intravenously injected cholylglycine was characterized in healthy man by a radioimmunoassay, specific for conjugates of cholic acid, on serial samples of venous blood. Cholylglycine disappearance was rapid (mean half-life ± S.E. = 2.6 ± 0.1 minutes) and of first-order kinetics; the rate of disappearance was independent of dose between 2 and 15 μmoles per kilogram of body weight. A dose of 5 μmoles per kilogram was selected as an optimal dose, and its clearance was defined in 45 healthy subjects. After intravenous injection of this dose, conjugates of cholic acid increased 10-fold, but in all subjects the concentration of these bile acids had returned to 1 μM (the upper limit of normal, fasting state) by 10 minutes. No side effects were observed. (N Engl J Med 292:1205–1209, 1975), WHEN given intravenously, bile acids are rapidly cleared by the liver and secreted into bile.