Journal of Lipid Research, Vol 34, 429-435, Copyright © 1993 by Lipid Research, Inc.
Metabolism of sulfonate analogs of ursodeoxycholic acid and their effects on biliary bile acid composition in hamsters
T Mikami, K Kihira, S Ikawa, M Yoshii, S Miki, EH Mosbach and T Hoshita
Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, Japan.
The metabolism of sodium 3 alpha,7 beta-dihydroxy-5 beta-cholane-24-
sulfonate and sodium 3 alpha,7 beta-dihydroxy-24-nor-5 beta-cholane-23-
sulfonate was studied in hamsters. In bile fistula animals these sulfonate
analogs of ursodeoxycholic acid were absorbed mainly from the terminal
ileum and secreted rapidly into the bile without biotransformation or
conjugation. After oral administration, the sulfonate analogs were excreted
in the feces at the same rate as chenodeoxycholic acid and its metabolic
products. The intestinal microorganisms transformed chenodeoxycholic acid
largely into lithocholic acid; the sulfonate analogs were completely
resistant to biotransformation. After a 2-week feeding period, the
sulfonate analogs of ursodeoxycholic acid accounted for 24.0% and 16.9% of
total biliary bile acids. These sulfonates did not affect the proportions
of the natural bile acids in the bile, and the ratio of glycine-conjugated
bile acids to taurine-conjugated bile acids was not altered by feeding the
sulfonates. In contrast, when ursodeoxycholic acid was fed, the proportions
of the natural bile acids and the glycine/taurine ratio were changed. These
results suggest that the sulfonate analogs had no profound effect on
endogenous bile acid metabolism and did not cause a depletion of the
hepatic taurine pool during enterohepatic circulation. The sulfonates had
no effect on intestinal cholesterol absorption and serum cholesterol
levels.