Premium
Kinetic analysis of hexose transport to determine the mechanism of amygdalin and prunasin absorption in the intestine
Author(s) -
Wagner Brent,
Galey William R.
Publication year - 2003
Publication title -
journal of applied toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.784
H-Index - 87
eISSN - 1099-1263
pISSN - 0260-437X
DOI - 10.1002/jat.934
Subject(s) - amygdalin , chemistry , glycoside , d glucose , hexose , monosaccharide , sodium , phlorizin , mannose , cotransporter , galactose , chromatography , glucose transporter , biochemistry , stereochemistry , endocrinology , biology , organic chemistry , medicine , alternative medicine , pathology , insulin , enzyme
Evidence is accumulating that glucose‐conjugated compounds may be carried across the gut mucosa via the epithelial sodium‐dependent monosaccharide transporter SGLT1. A modication of the everted intestinal sac technique was utilized to study the transport of the cyanogenic glycoside amygdalin ( d ‐mandelonitrile β ‐ d ‐gentiobioside) and its metabolite d ‐mandelontrile β ‐ d ‐glucoside (prunasin). Everted sacs of rat jejunum and ileum were bathed in isotonic oxygenated sodium chloride–potassium phosphate buffer containing 2.8 µCi d ‐[ 3 H]‐mannose and 0.187 µCi d ‐[ 14 C]‐glucose. For treatment groups, buffers contained phloridzin, galactose, amygdalin or prunasin. The rate constant ( k ) for the transport process was calculated. Compared with the control ( n = 33), phloridzin ( n = 25) signicantly reduced the rate constants of both d ‐[ 14 C]‐glucose and d ‐[ 3 H]‐mannose. Substitution of sodium with choline and incremental galactose treatments similarly reduced d ‐[ 14 C]‐glucose inux, indicating that a fraction of the transport is carrier‐mediated. Treatment with amygdalin did not signicantly affect the rate constants of d ‐[ 14 C]‐glucose or d ‐[ 3 H]‐mannose transport. However, treatment with 1 mM prunasin ( n = 16) did reduce the inux of d ‐[ 14 C]‐glucose without affecting d ‐[ 3 H]‐mannose values. This is consistent with the reports nding that glycoside absorption may be mediated by SGLT1. Copyright © 2003 John Wiley & Sons, Ltd.