Hexose transport across the basolateral membrane of the chicken
jejunum.
Garriga, Carles, Miquel Moret, and Juana M. Planas.
Unitat de Fisiologia, Facultat de Farm[grave]acia, Universitat de
Barcelona, Av. Joan XXIII s/n, E-08028, Barcelona, Spain
APStracts 3:0380R, 1996.
The characteristics of the basolateral transport of D-glucose (D-Glc)
and D-fructose (D-Fru) have been studied in membrane vesicles from
the jejunum of 5-6 wk-old chickens. Uptake of hexoses was measured
using a rapid filtration method. The maximal rate of transport (Vmax)
for D-Glc was 2.36 nmol/mg.s and for D-Fru was 3.79 nmol/mg.s. The
Michaelis constants were 17.3 mmol/L for D-Glc and 40.4 mmol/L for D
-Fru. D-Glc inhibited its own transport (Ki= 17.4 mmol/L) and the
transport of D-Fru (Ki= 18.7 mmol/L). D-Fru inhibited its own
transport (Ki= 38.1 mmol/L) and the transport of D-Glc (Ki= 40.3
mmol/L). The transport of both hexoses was Na+-independent,
theophylline and cytochalasin B-sensitive and showed cis-inhibition
by structural analogues. In preloaded vesicles, the uptake of D-Fru
was trans-stimulated by D-Glc and 2-deoxy-D-glucose. These properties
indicate the presence of a low-affinity high-capacity, GLUT2-type
carrier in the chicken intestine, responsible for moving both D-Glc
and D-Fru across the basolateral membrane.
Received 13 June 1996; accepted in final form 17 October 1996.
APS Manuscript Number R342-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996