Radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid from human serum, with use of 125I-labeled ligands.
We describe a method for radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid in serum. In the method, 125I-labeled bile acid conjugates are used as the tracers along with antibodies raised against individual bile acid-bovine serum albumin conjugates. Antibody-bound and free bile acids were separated by polyethylene glycol precipitation (final concentration, 125 g/L). Before radioimmunoassay, 0.1-mL serum samples were precipitated with nine volumes of ethanol, and portions from the supernate were used in the assays. The lowest measurable amounts of the bile acids, expressed as pmol/tube, were: cholic acid conjugates, 2; chenodeoxycholic acid conjugates, 0.5; and deoxycholic acid conjugates. 2. Analytical recovery of bile acids added to bile acid-free serum ranged from 85 to 110%; intra-assay and inter-assay CVs ranged from 3.2 to 5.3% and from 5.3 to 12.2%, respectively. Concentrations (mean +/- SD) of the bile acid conjugates in serum from apparently healthy women and men (in mumol/L) were: cholic acid conjugates, 0.43 +/- 0.17 (n = 126); chenodeoxycholic acid conjugates, 0.47 +/- 0.23 (n = 111); and deoxycholic acid conjugates, 0.33 +/- 0.11 (n = 96). The values for primary bile acids were greatly increased in patients with various hepatobiliary diseases.
D002635:Chenodeoxycholic Acid / Q000031:analogs & derivatives* / Q000097:blood; D002779:Cholestasis / Q000097:blood; D002793:Cholic Acids / Q000097:blood*; D003840:Deoxycholic Acid / Q000031:analogs & derivatives* / Q000097:blood; D005260:Female; D006505:Hepatitis / Q000097:blood; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood; D011863:Radioimmunoassay
D002793:Cholic Acids; D003840:Deoxycholic Acid; D002635:Chenodeoxycholic Acid