Bile Acid and Cholesterol Metabolism in the Mouse as Affected by Gholestyramine.

Abstract

Summary Dietary cholestyramine (MK 135) increased the rate of mobilization of blood and liver cholesterol in mice. The bile acid turnover rate in normal mice was 5 days, in mice treated with 1% cholestyramine, 1¼ days, or 4 times as fast. Bile acid pool size was 5.62 ± 1.09 mg in normals, 4.58 ± 0.65 in cholestyramine-treated mice. The pool was shown to consist almost exclusively of cholic acid and this spectrum was not altered by cholestyramine. The daily rate of synthesis of bile acids in normal mice was 0.56 mg, 1.84 mg in cholestyramine-treated mice. Digi-tonin precipitable fecal sterol excretion was 5.54 mg day in normal mice, 7.58 mg/day in mice treated with 1% MK 135. No conclusion could be reached as to whether the increased rate of mobilization of accumulated cholesterol affected by MK 135 was due to the increased excretion of either the fecal bile acid or sterol fraction exclusively, or was attributable to the excretion of both these fractions. We wish to acknowledge the excellent technical assistance of Mrs. J. Bertasius. We also wish to thank Merck Sharp and Dohme Research Laboratories for a generous gift of cholestyramine.