Direct measurement of first-pass ileal clearance of a bile acid in humans

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Gastroenterology; (USA)

OSTI ID:5855614

Galatola, G; Jazrawi, R P; Bridges, C; Joseph, A E; Northfield, T C ^[1]

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1. St. George's Hospital Medical School, London (England)

The purpose of this study was to develop and validate a method of directly measuring ileal bile acid absorption efficiency during a single enterohepatic cycle (first-pass ileal clearance). This has become feasible for the first time because of the availability of the synthetic gamma-labeled bile acid 75Selena-homocholic acid-taurine (75SeHCAT). Together with the corresponding natural bile acid cholic acid-taurine (labeled with 14C), SeHCAT was infused distal to an occluding balloon situated beyond the ampulla of Vater in six healthy subjects. Completion of a single enterohepatic cycle was assessed by obtaining a plateau for 75SeHCAT activity proximal to the occluding balloon, which prevented further cycles. Unabsorbed 75SeHCAT was collected after total gut washout, which was administered distal to the occluding balloon. 75SeHCAT activity in the rectal effluent measured by gamma counter was compared with that of absorbed 75SeHCAT level measured by gamma camera and was used to calculate first-pass ileal clearance. This was very efficient (mean value, 96%) and showed very little variation in the six subjects studied (range, 95%-97%). A parallel time-activity course in hepatic bile for 14C and 75Se during a single enterohepatic cycle, together with a ratio of unity for 14C/75Se in samples obtained at different time intervals, suggests that 75SeHCAT is handled by the ileum like the natural bile acid cholic acid-taurine. Extrapolation of 75SeHCAT first-pass ileal clearance to that of the natural bile acid therefore seems justifiable. In a subsidiary experiment, ileal absorption efficiency per day for 75SeHCAT was also measured by scanning the gallbladder area on 5 successive days after the measurement of first-pass ileal clearance. In contrast with absorption efficiency per cycle, absorption efficiency per day varied widely (49%-86%).

• OSTI ID: 5855614
• Journal Information: Gastroenterology; (USA), Journal Name: Gastroenterology; (USA) Vol. 100:4; ISSN GASTA; ISSN 0016-5085
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BETA DECAY RADIOISOTOPES
BILE ACIDS
BILIARY TRACT
BODY
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CLEARANCE
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
GASTROINTESTINAL TRACT
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTESTINES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MEASURING METHODS
METABOLISM
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
SELENIUM 75
SELENIUM ISOTOPES
SMALL INTESTINE
STEROIDS
STEROLS
TRACER TECHNIQUES