Development of an Intravenous Bile Acid Tolerance Test

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 cholyglycine was characterized in healthy man by a radiommunoassay, specific for conjugates of cholic acid, on serial samples of venous blood. Cholylglycine disappearance was rapid (mean half-life plus or minus S.E. equals 2.6 plus or minus 0.1 minutes) and of first-order kinetics; the rate of disappearance was independent of dose between 2 and 15 mumoles per kilogram of body weight. A dose of 5 mumoles 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 muM (the upper limit of normal, fasting state) by 10 minutes. No side effects were observed.