Carrier-mediated system for transport of biotin in rat intestine in vitro

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:6218754

Said, H M; Redha, R

Transport of biotin was examined in rat intestine using the everted sac technique. Transport of 0.1 ..mu..M biotin was linear with time for at least 30 min of incubation and occurred at a rate 3.7 pmol g initial tissue wet wt/sup -1/ min/sup -1/. Transport of biotin was higher in the jejunum than the ileum and was minimum in the colon (85 +/- 6, 36 +/- 6, and 2.8 +/- 0.6 pmol x g initial tissue wet wt/sup -1/ x 25 min/sup -1/, respectively). In the jejunum, transport of biotin was saturable at low concentrations but linear at higher concentrations. The transport of low concentrations of biotin was 1) inhibited by structural analogues (desthiobiotin, biotin methyl ester, diaminobiotin, and biocytin), 2) Na/sup +/ dependent, 3) energy dependent, 4) temperature dependent, and 5) proceeded against a concentration gradient in the serosal compartment. No metabolic alteration occurs to the biotin molecule during transport. This study demonstrates that biotin transport in rat intestine occurs by a carrier-mediated process at low concentrations and by simple diffusion at high concentrations. Furthermore, the carrier-mediated process is Na/sup +/, energy, and temperature dependent.

• Research Organization: Vanderbilt Univ. School of Medicine, Nashville, TN
• OSTI ID: 6218754
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:1; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION
ANIMALS
AZOLES
BIOTIN
BODY
CARBOXYLIC ACIDS
CHROMATOGRAPHY
COUNTING TECHNIQUES
DIGESTIVE SYSTEM
GASTROINTESTINAL TRACT
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
IMIDAZOLES
INTESTINAL ABSORPTION
INTESTINES
LABELLED COMPOUNDS
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
RATS
RODENTS
SCINTILLATION COUNTING
SEPARATION PROCESSES
SMALL INTESTINE
TEMPERATURE DEPENDENCE
THIN-LAYER CHROMATOGRAPHY
TRITIUM COMPOUNDS
UPTAKE
VERTEBRATES
VITAMIN B GROUP
VITAMINS