Development of enzymatic determination of 3-keto bile acids in serum

Abstract

An enzymatic method for the quantitative determination of 3-keto bile acid by using of 3-keto-5β-Δ⁴-dehydrogenase was developed. The data on specificity, reproducibility, sensitivity and accuracy of this assay were satisfactory, and close agreement between the values by this enzymatic method and those determined by gas-liquid chromatography was observed. Consequently this method allowed quantitation of 3-keto bile acids in serum.
Then, dehydrocholic acid (DHCA) disappearance curve in serum of healthy subjects and patients with liver cirrhosis after intravenous administration of 1g DHCA was analyzed by using this enzymatic method. In healthy subjects, serum DHCA concentration at 1 minute after loading reached to 364.6μM (in average), and then rapidly reduced to 37.1μM at 20 minutes and 14.6μM at 30 minutes. On the other hand, in patients with liver cirrhosis the clearance of DHCA in serum was significantly delayed, compared with that of healthy subjects.