Hepatic bile acid metabolism during early development revealed from the analysis of human fetal gallbladder bile

K. D R Setchell, R. Dumaswala, C. Colombo, M. Ronchi

Research output: Contribution to journalArticlepeer-review

Abstract

A detailed study of the qualitative and quantitative composition of bile acids in human fetal gallbladder bile is described. Bile was collected during early gestation (weeks 16-19) and analyzed by gas chromatography mass spectrometry, fast atom bombardment ionization mass spectrometry, and high performance liquid chromatography. Bile acids were separated into different conjugate groups by chromatography on the lipophilic anion exchange gel, diethylaminohydroxypropyl Sephadex LH-20. Quantitatively more than 80% of the bile acids were secreted into bile conjugated to taurine. Unconjugated bile acids and glycine conjugates accounted for 5-10% of the total biliary bile acids. Bile acid sulfates were present only in trace amounts indicating that quantitatively sulfation is not an important pathway in bile acid metabolism during development. Total biliary bile acid concentrations were low (0.1-0.4 mM) when compared to reported values for adult bile (> 10 mM). Chenodeoxycholic acid was the major biliary bile acid and exceeded cholic acid concentrations by 1.43-fold indicating either a relative immaturity in 12α-hydroxylase activity during early life or a dominance of alternative pathways for chenodeoxycholic acid synthesis. A relatively large proportion of the biliary bile acids comprised metabolites not found in adult bile. The presence of relatively high proportions of hyocholic acid (often greater than cholic acid) and several 1β-hydroxycholanoic acid isomers indicates that C-1 and C-6 hydroxylation are important pathways in bile acid synthesis during development. We describe, for the first time, evidence for the existence of a C-4 hydroxylation pathway in the metabolism of bile acids, which may be unique to early human development. Mass spectrometry was used to confirm the identification of 3α,4β,7α-trihydroxy-5β-cholanoic and 3α,4β-dihydroxy-5β-cholanoic acids. Quantitatively, these C-4 hydroxylated bile acids accounted for 5-15% of the total biliary bile acids of the fetus, suggesting that C-4 hydroxylation is quantitatively an important pathway in the bile acid metabolism during early life.

Original languageEnglish
Pages (from-to)16637-16644
Number of pages8
JournalJournal of Biological Chemistry
Volume263
Issue number32
Publication statusPublished - 1988

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Hepatic bile acid metabolism during early development revealed from the analysis of human fetal gallbladder bile'. Together they form a unique fingerprint.

Cite this