Kinetics for the synthetic bile acid 75-selenohomocholic acid-taurine in humans: comparison with (/sup 14/C)taurocholate

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · Gastroenterology; (United States)

OSTI ID:6924275

Jazrawi, R P; Ferraris, R; Bridges, C; Northfield, T C

The apparent fractional turnover rate of the gamma-labeled bile acid analogue 75-selenohomocholic acid-taurine (75-SeHCAT) was assessed from decline in radioactivity over the gallbladder area on 4 successive days using a gamma-camera, and was compared in the same subjects with the fractional turnover rate of the corresponding natural bile acid, cholic acid-taurine, labeled with 14C ((14C)CAT) using the classical Lindstedt technique. Very similar results were obtained in 5 healthy individuals (coefficient of variation 4.8%, medians 0.35 and 0.34, respectively). By contrast, the fractional deconjugation rate assessed from zonal scanning of glycine- and taurine-conjugated bile acids on thin-layer chromatography was much less for 75-SeHCAT than for (14C)CAT (0.02 and 0.13, respectively; p less than 0.05). The fractional rate for deconjugation plus dehydroxylation was also determined by zonal scanning, and gave lower values for 75-SeHCAT than for (14C)CAT (0.02 and 0.12, respectively; p less than 0.05). There was a striking similarity between the fractional rate for deconjugation alone and that for deconjugation plus dehydroxylation for both bile acids in individual samples (r = 0.999, p less than 0.001), suggesting that these two processes might occur simultaneously and probably involve the same bacteria. We conclude that our scintiscanning technique provides an accurate, noninvasive method of measuring fractional turnover rate of a bile acid in humans, and that the finding that 75SeHCAT remains conjugated with taurine during enterohepatic recycling means that absorption should be specific for the ileal active transport site, thus rendering it an ideal substance for assessing ileal function.

• Research Organization: St. George's Hospital Medical School, London (England)
• OSTI ID: 6924275
• Journal Information: Gastroenterology; (United States), Journal Name: Gastroenterology; (United States) Vol. 95:1; ISSN GASTA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ABDOMEN
BETA DECAY RADIOISOTOPES
BILE ACIDS
BILIARY TRACT
BODY
BODY AREAS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHOLIC ACID
CHROMATOGRAPHY
COMPARATIVE EVALUATIONS
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
GASTROINTESTINAL TRACT
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTESTINES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
METABOLISM
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPE SCANNING
RADIOISOTOPES
SCINTISCANNING
SELENIUM 75
SELENIUM ISOTOPES
SEPARATION PROCESSES
SMALL INTESTINE
STEROIDS
STEROLS
THIN-LAYER CHROMATOGRAPHY
TRACER TECHNIQUES