| Abstract: | We have developed an isotope dilution method for determination of deoxycholic acid pool size and input rate which employs oral administration of 50 mg of 24-13C]deoxycholic acid and serum sampling. The method has been validated by classical isotope dilution technique using 24-14C]deoxycholic acid and bile sampling in five patients with colonic adenomas. Excellent agreement between pool sizes and input rates determined with 13C/12C isotope ratio measurements in serum and 14C measurements in bile was obtained when isotope ratios were measured in the conjugated fraction of deoxycholic acid in serum. We conclude that pool size and input rate of deoxycholic acid can accurately be determined by blood sampling after oral administration of 24-13C]deoxycholic acid, therewith eliminating the use of radioactive tracers and the need for bile sampling. |
