Regulation of Intestinal Sugar Transport.
Ferraris, Ronaldo P., and Jared Diamond.
Physiology Dept., University of Medicine and Dentistry of New Jersey, New
jersey Medical School, Newark, Jew Jersey; and Physiology Dept., University of
California Medical School, Los Angeles, California
APStracts 2:0038P, 1996.
ABSTRACT
The recent surge in knowledge of cellular and molecular mechanisms of
intestinal sugar transport has fueled an enormous interest in adaptive
mechanisms regulating sugar transport. We first review several functional
considerations that help us interpret the different patterns of adaptation for
different nutrients. We then distinguish nonspecific adaptive mechanisms
leading to parallel changes in transport of differnet nutrients from specific
adaptive mechansims only affecting the transport of a single nutrient.
Nonspecific adaptive mechanisms include changes in mucosal surface area and in
the ratio of transporting to nontransporting cells; specific mechanisms
include changes in site density of transporters and in affinity constants. We
also enumerate the patterns of regulation and describe how sugar transport is
affected by changes in diet, energy budgets, and environmental salinity as
well as by intestinal resection, starvation, stress, and age. We relate the
various signals linking these stimuli to adaptive mechanisms and make
predictions about the nature of these signals. Finally, we describe the
significance of the interactions among sugar, fluid, and electrolyte transport
mechanisms and of the paracellular pathway to transepithelial transport of
sugars. We close by drawing attention to promising directions for future
research.
APS Manuscript Number P-6.
Article publication pending January 1997, Physiological Reviews.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 November 1996