Bile acids in plasma of patients without kidneys

Abstract

Bile acids were measured in plasma of three non-fasting bilaterally nephrectomized patients in chronic haemodialysis. After separation of the bile acid mixture according to mode of conjugation and cleavage of amide and sulphate ester bonds, the bile acids were analysed as their methylester trimethylsilyl ethers on gas—liquid chromatography—mass spectrometry (GC—MS). The total bile acid concentration was 4.10–13.70 μmol·l⁻¹ (N:<14 μmol·l⁻¹) mostly glycine conjugates. Unconjugated bile acids were found in significant amounts in one patient and in trace amounts in another patient. Chenodeoxycholic acid was the predominant individual bile acid constituting 1.89–6.79 μmol·l⁻¹ (N:<10 μmol·l⁻¹). The oxidoreduction product of this bile acid: ursodeoxycholic acid, was found in all patients, whereas the 7α-dehydroxylation product: lithocholic acid, was absent. 1β-hydroxy-deoxycholic acid was a major constituent in two of the cases. Hyocholic acid, the 6α-hydroxylation product of chenodeoxycholic acid was detected in two cases. Tetrahydroxy bile acids and sulphated bile acids were not found in significant amounts.

Key-words:

• bile acids
• haemodialysis
• plasma
• uraemia