Inhibition of ileal bile acid absorption by colestimide

BACKGROUND: Colestimide is a new type of anion-exchange resin in Japan, but its effect on bile acid absorption in the ileum has not been studied. METHODS: Absorption of ursodeoxycholate, tauroursodeoxycholate, cholate, taurocholate and taurolithocholate-sulfate in rat ileum was compared in the presence and absence of colestimide. Bile acid adsorption by colestimide in vitro was also studied. RESULTS: All bile acids were efficiently absorbed by the ileum, and the cumulative absorption during 60 min was 25-78%. The absorption of ursodeoxycholate, tauroursodeoxycholate and taurocholate was inhibited by colestimide, whereas that of cholate and taurolithocholate-sulfate was not inhibited by colestimide. Adsorption of bile acids by colestimide in vitro was higher with taurine conjugates than with the unconjugated forms. CONCLUSIONS: Colestimide was shown to be useful to inhibit the physiologically important ileal absorption of bile acid amides in vivo.