Effect of chenodeoxycholic acid on biliary and urinary bile acids and bile alcohols in cerebrotendinous xanthomatosis; monitoring by high performance liquid chromatography.

Biliary and urinary bile alcohol and bile acid composition has been determined by high performance liquid chromatography in patients with cerebrotendinous xanthomatosis before and after treatment with chenodeoxycholic acid. Most of the bile acids and bile alcohols in the bile and urine were separated in less than 30 min using a radial pack C18 muBondapak 5 micron particle size column with a mobile phase of acetonitrile-water-methanol-acetic acid 70:70:20:1 (v/v/v/v) at a flow rate of 2 ml/min, and a refractive index detector. Before treatment, cholic acid (49%) and 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 25-tetrol (27%) were the major biliary bile acid and bile alcohol, respectively, but were not detected in the urine of five patients. 5 beta-Cholestane-pentols were, instead, the major urinary bile alcohols with 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 23 xi, 25-pentol (56%) predominating. Whereas 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 24S,25-pentol was not detected in the bile, it was isolated in the urine of all patients (27%). The only urinary bile acid isolated by high performance liquid chromatography was nor-cholic acid. After 1 month of treatment with chenodeoxycholic acid, 0.75 g/day, chenodeoxycholic acid became the major bile acid in the bile of all patients (71%) along with its metabolite, ursodeoxycholic acid (21%). Cholic acid and 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 25-tetrol were drastically reduced and were only 3% each. The excretion of 5 beta-cholestane-pentols in the urine was also drastically reduced from 130 mg/day to 15 mg/day.