Effect of colestimide on absorption of unconjugated bile acids in the rat jejunum

Background: Colestimide is a newly developed bile acid-binding resin in Japan, but its bile acid-binding properties have not been studied. Methods: The absorption of unconjugated bile acids (5 mmol/L) in the ligated rat jejunum was compared in the presence and absence of colestimide. Furthermore, bile acid adsorption by colestimide was also studied in vitro. Results: All bile acids were efficiently absorbed in the jejunum and the cumulative absorption during 120 min was 29-63%. The absorption of chenodeoxycholate, lithocholate, deoxycholate and ursodeoxycholate was dose-dependently inhibited by 2.5 and 5 mg colestimide, whereas the absorption of cholate was not inhibited, even in the presence of 5 mg colestimide. Adsorption of bile acids by colestimide in vitro was approximately 60% for chenodeoxycholate, lithocholate, deoxycholate and ursodeoxycholate, whereas the adsorption of cholate was low (16%). Conclusions: Jejunal absorption of ursodeoxycholate was inhibited by colestimide to a similar extent as other dihydroxy bile acids, whereas that of cholate was not inhibited under the same conditions.