The Metabolic Sequence for the Occurrence of an Anomalous Bile Acid, 12-Ketochenodeoxycholic Acid, Found in the Bile of Hepatobiliary Diseased Patients
The metabolic sequence for the occurrence of an anomalous bile acid, 12-ketochenodeoxycholic acid (12-KCCA),* found in the bile of patients with hepatobiliary diseases was disclosed. 1. The H-1 strain of Staphylococcus epidermidis isolated from the fistula bile of a patient, in which conjugated 12-KCCA was detected, showed fairly strict substrate specificity for 12α-hydroxysteroid dehydrogenation among bile acids and alcohols. 2. Only the H-1 strain had the ability to dehydrogenate cholic acid at 12-position, but a hundred strains of Staph. epidermidis collected either from nasal cavities or indoor air did not. 3. Labeled 12-KCCA administered peros to rats remained unchanged in the intestinal cavity, while it was converted predominantly to taurocholate during the enterohepatic circulation. 4. The 12-ketosteroid reductase was shown to be present in the rat liver homogenate and to localize predominantly in the microsomal fraction. 5. Based on these observations, a possible metabolic sequence was presented.