Effect of chronic administration of ursodeoxycholic acid on the ileal absorption of endogenous bile acids in man

Abstract

The effect of long-term administration of ursodeoxycholic acid on the ileal absorption of endogenous bile acids was determined using the tauro 23 (⁷⁵Se) selena-25 homotaurocholic acid test in a controlled double-blind study involving healthy subjects (n = 15). Subjects received placebo or 13 to 15 mg/kg/day ursodeoxycholic acid for 5 wk. In the placebo group (n = 7) there was no change in the composition of serum bile acids or in the mean percentage of retention of tauro 23(⁷⁵Se) selena-25 homotaurocholic acid (36.1% ± 6.0% vs. 38.7% ± 6.7%). In contrast, in the ursodeoxycholic acid group, serum ursodeoxycholic acid conjugates increased and the percentage of retention of tauro 23 (⁷⁵Se) selena-25 homotaurocholic acid fell from 45.8% ± 6.8% to 20.5% ± 5.7% (p < 0.01). We conclude that ursodeoxycholic acid administration reduces ileal absorption of endogenous bile acids. These findings provide a rational explanation for the changes in the composition of the bile acid pool during ursodeoxycholic acid therapy and could have important therapeutic implications. (HEPATOLOGY 1990;12:1206-1208).