DETERMINATION OF SERUM BILE ACIDS IN HEPATOBILIARY DISEASES BY GAS LIQUID CHROMATOGRAPHY : FASTING SERUM BILE ACID LEVELS AND ENDOGENOUS BILE ACID TOLERANCE TEST

The methods and results of a gas-liquid chromatographic analysis of bile acids in serum are presented. The analysis of bile acids in serum involves enzymatic hydrolysis (cholylglycine hydrolase), preparation of propionated methyl ester derivatives of bile acid and gas chromatographic procedure with 2.5 % OV-1.

Adequate separation of the individual bile acids, (cholic, chenodeoxycholic and deoxycholic acid) was achieved with vitamine E caprylate as an internal standard. A detector response was linear and recovery of radioactive taurocholic acid and non-radioactive vitamine E caprylate added to the serum was 82.10±6.86 and 80.96±1.62% respectively. The serum fasting bile acid concentrations of normal controls were 3.17±2.34 for total bile acids, 1.17±1.25 for cholic acid, 1.34±2.11 for chenodeoxycholic acid and 1.29±0.95 μg/ml for deoxycholic acid. The differences in the serum total bile acid levels, magnitude of the increase in the serum concentration between cholic and chenodeoxycholic acid and serum concentration level of deoxycholic acid which were all characterized in various hepatobiliary diseases seemed to be useful for the diagnosis and differential diagnosis of hepatobiliary diseases. However, these serum bile acid concentrations were frequently observed overlapped in some of the individuals among hepatobiliary diseases. An endogenous bile add tolerance test with 2 μg/kg caerulein injection demonstrated more distinction in serum bile acid levels between normal and chronic active hepatitis and between chronic active hepatitis and liver cirrhosis than indicated by a fasting total bile acid level alone.

Percent chenodeoxycholic acid increased more than any other individual bile acids during the endogenous bile acid tolerance test suggesting the most important role of chenodeoxycholic acid.