Steady-state kinetics of serum bile acids in healthy human subjects: single and dual isotope techniques using stable isotopes and mass spectrometry

Journal Article · Sun Mar 01 04:00:00 EST 1987 · J. Lipid Res.; (United States)

OSTI ID:6501379

Everson, G T

Techniques have been developed for the measurement of the complete steady-state kinetics of both chenodeoxycholic (CDCA) and cholic (CA) acid and the pool size of deoxycholic acid (DCA) from the serum of healthy subjects using stable isotopes and capillary gas-liquid chromatography-mass spectrometry (GLC-MS). Serum bile acids were purified by a method employing a C18 chromatographic cartridge, acid solvolysis, enzymic hydrolysis, methylation, a C8 chromatographic cartridge, and TMS-ether derivatization. Fifty mg each of (24-/sup 13/C)CDCA and (24-/sup 13/C)CA was given to five healthy subjects and kinetics were measured from serum and bile. In each case, the measurements from serum (S) equalled those from bile (B) (CDCA (S vs. B): fractional turnover rate (FTR) (d-1) 0.17 +/- 0.03 vs. 0.18 +/- 0.04; pool (g) 0.64 +/- 0.1 vs. 0.68 +/- 0.14, synthesis (g d-1) 0.12 +/- 0.03 vs. 0.1 +/- 0.03; CA (S vs. B): FTR (d-1) 0.28 +/- 0.05 vs. 0.29 +/- 0.07, pool (g) 0.84 +/- 0.29 vs. 0.82 +/- 0.29, synthesis (g d-1) 0.24 +/- 0.10 vs. 0.25 +/- 0.12). In addition, a dual isotope technique for measuring the steady-state kinetics of CDCA was developed using (11,12-2H)CDCA, (24-/sup 13/C)CDCA, and a single sample of serum. In ten subjects, the FTR, pool and synthesis of CDCA measured from serum was similar to that measured from bile. Finally, a technique for estimating the deoxycholic acid (DCA) pool from serum using the ratio of the 370 ion of DCA to that of CDCA was developed. In summary, these data demonstrate that the steady-state kinetics of CDCA and CA and the pool size of DCA can be measured from the serum of healthy subjects.

• Research Organization: Univ. of Colorado School of Medicine, Denver
• OSTI ID: 6501379
• Journal Information: J. Lipid Res.; (United States), Journal Name: J. Lipid Res.; (United States) Vol. 3; ISSN JLPRA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BILE ACIDS
BIOCHEMICAL REACTION KINETICS
CARBON 13
CARBON ISOTOPES
CARBOXYLIC ACIDS
CHROMATOGRAPHY
DEUTERIUM
EVEN-ODD NUCLEI
GAS CHROMATOGRAPHY
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
LIQUID COLUMN CHROMATOGRAPHY
MASS SPECTROSCOPY
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
REACTION KINETICS
SEPARATION PROCESSES
SPECTROSCOPY
STABLE ISOTOPES
STEROIDS
STEROLS
TRACER TECHNIQUES