Increased sulfation of lithocholate in patients with cholesterol gallstones during chenodeoxycholate treatment

Chenodeoxycholate was administered to 13 patients with cholesterol gallstones. During the treatment period the bile composition changed markedly. Chenodeoxycholate increased from 42.9% of the total bile salts before treatment to 79.3% after 8 weeks of treatments. Ursodeoxycholate increased from 2.3 to 12.6% and lithocholate from 1.1 to 3.3%. In contrast, cholate decreased from 40.3% of the total bile salts to 3.1% and deoxycholate decreased from 12.5 to 2.5%. Less than 5% of chenodeoxycholate, ursodeoxycholate, cholate and deoxycholate in bile were sulfate esters. In contrast, considerable amounts of lithocholate were sulfated. The sulfation of lithocholate increased from 32.8% of the total lithocholate before treatment to 73.9% after 8 weeks of treatment. Sulfated lithocholate is more rapidly eliminated in feces and urine than the nonsulfated compound. Furthermore, sulfated lithocholate is less toxic. Therefore, the increase in the sulfation of lithocholate observed in most of our patients represents a protective mechanism.