skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Intestinal transport: studies with isolated epithelial cells

Abstract

Isolated intestinal epithelial cells have been extremely useful for characterizing the nature of intestinal absorption processes and for providing insight into the energetics of Na/sup +/-dependent transport systems. This report describes a number of experimental approaches which have been used for investigating the specific epithelial transport systems involved in sugar absorption, but provides information which ultimately should prove useful for characterizing a number of different intestinal transport events. Similar experiments should also prove useful for exploring the effect of environmental agents on the function of intestinal tissue. In the case of sugars, net absorption is accomplished via a mucosal, Na/sup +/-dependent concentrative transport system acting in sequence with a passive serosal system which does not require Na/sup +/. The serosal system limits the full gradient-forming capability of the muscosal system. Agents such as phloretin or cytochalasin B which inhibit serosal transport allow the cells to establish sugar gradients as high as 70 fold in contrast to 10 to 15 fold gradients observed for control cells. Sevety-fold sugar gradients cannot be explained in terms of the energy available in the electrochemical potential for Na/sup +/ if the Na/sub 2/: sugar coupling stoichiometry is 1:1 as commonly assumed. New information indicates thatmore » the true Na/sup +/:sugar stoichiometry is in fact 2:1. Flow of two Na/sup +/ ions per sugar molecule down the transmembrane electrochemical potential for Na/sup +/ provides more than sufficient energy to account for observed 70 fold sugar gradients. If flow of sugar by other routes could be completely inhibited, theoretical sugar gradients as high as 400 could be achieved assuming that the cells maintain a membrane potential of -36 mV as measured for intact tissue.« less

Authors:
Publication Date:
Research Org.:
Univ. of Rochester Medical Center, NY
OSTI Identifier:
6503267
Resource Type:
Journal Article
Journal Name:
Environ. Health Perspect.; (United States)
Additional Journal Information:
Journal Volume: 33
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; INTESTINAL ABSORPTION; BIOCHEMICAL REACTION KINETICS; MEMBRANE TRANSPORT; CARBON 14 COMPOUNDS; CELL CULTURES; CHICKENS; ELECTRIC POTENTIAL; ELECTROCHEMISTRY; EPITHELIUM; INTESTINES; MEMBRANES; SACCHAROSE; SODIUM; ABSORPTION; ALKALI METALS; ANIMAL TISSUES; ANIMALS; BIRDS; BODY; CARBOHYDRATES; CHEMISTRY; DIGESTIVE SYSTEM; DISACCHARIDES; ELEMENTS; FOWL; GASTROINTESTINAL TRACT; KINETICS; LABELLED COMPOUNDS; METALS; OLIGOSACCHARIDES; ORGANIC COMPOUNDS; ORGANS; REACTION KINETICS; SACCHARIDES; TISSUES; UPTAKE; VERTEBRATES; 550201* - Biochemistry- Tracer Techniques; 550301 - Cytology- Tracer Techniques

Citation Formats

Kimmich, G.A. Intestinal transport: studies with isolated epithelial cells. United States: N. p., 1979. Web. doi:10.1289/ehp.793337.
Kimmich, G.A. Intestinal transport: studies with isolated epithelial cells. United States. doi:10.1289/ehp.793337.
Kimmich, G.A. Sat . "Intestinal transport: studies with isolated epithelial cells". United States. doi:10.1289/ehp.793337.
@article{osti_6503267,
title = {Intestinal transport: studies with isolated epithelial cells},
author = {Kimmich, G.A.},
abstractNote = {Isolated intestinal epithelial cells have been extremely useful for characterizing the nature of intestinal absorption processes and for providing insight into the energetics of Na/sup +/-dependent transport systems. This report describes a number of experimental approaches which have been used for investigating the specific epithelial transport systems involved in sugar absorption, but provides information which ultimately should prove useful for characterizing a number of different intestinal transport events. Similar experiments should also prove useful for exploring the effect of environmental agents on the function of intestinal tissue. In the case of sugars, net absorption is accomplished via a mucosal, Na/sup +/-dependent concentrative transport system acting in sequence with a passive serosal system which does not require Na/sup +/. The serosal system limits the full gradient-forming capability of the muscosal system. Agents such as phloretin or cytochalasin B which inhibit serosal transport allow the cells to establish sugar gradients as high as 70 fold in contrast to 10 to 15 fold gradients observed for control cells. Sevety-fold sugar gradients cannot be explained in terms of the energy available in the electrochemical potential for Na/sup +/ if the Na/sub 2/: sugar coupling stoichiometry is 1:1 as commonly assumed. New information indicates that the true Na/sup +/:sugar stoichiometry is in fact 2:1. Flow of two Na/sup +/ ions per sugar molecule down the transmembrane electrochemical potential for Na/sup +/ provides more than sufficient energy to account for observed 70 fold sugar gradients. If flow of sugar by other routes could be completely inhibited, theoretical sugar gradients as high as 400 could be achieved assuming that the cells maintain a membrane potential of -36 mV as measured for intact tissue.},
doi = {10.1289/ehp.793337},
journal = {Environ. Health Perspect.; (United States)},
number = ,
volume = 33,
place = {United States},
year = {1979},
month = {12}
}