Application of Gel Filtration of Bile Acids to Studies of Lipid-Complexes in Bile. ∗ †

Abstract

Summary

Gel filtration on Sephadex G-25 was applied to conjugated bile acids in water solution or in bile. 1. An adsorption of bile acids occurs during gel filtration. The adsorption was more pronounced when gel filtration was performed with saline than with water. Conjugates of monohydroxycholanic acid were adsorbed to the greatest extent followed by trihydroxycholanic acid and dihydroxycholanic acid. Rates of elution of taurine and glycine conjugates of a bile acid were about the same. 2. Labeled conjugated bile acids dissolved in bile or in vivo labeled conjugates, obtained by administration of the corresponding free acid to patients, showed the same behavior on gel filtration. The conjugates of cholic, deoxycholic and chenodeoxycholic acid were all absent from the molecular weight fraction (M > 3,500-4,500) and were eluted at about the same rate as the corresponding conjugates gel filtered in the absence of bile. A small amount of the lithocholic acid conjugates in bile were eluted in the macromolecular fraction. 3. Cholesterol and phospholipids in bile were eluted in the macromolecular fraction and thus were separated from the bile acids. A variable amount of cholesterol was recovered from the columns after gel filtration.

The results of gel filtration of bile constituents are discussed in relation to our present understanding of the physical state of lipids and bile acids in bile.