Learn More
We determined the extent of Na(+)-independent, proton-driven amino acid transport in human intestinal epithelia (Caco-2). In Na(+)-free conditions, acidification of the apical medium (apical pH 6.0, basolateral pH 7.4) is associated with a saturable net absorption of glycine. With Na(+)-free media and apical pH set at 6.0, (basolateral pH 7.4), competition(More)
beta-Alanine transport across intact human intestinal epithelial (Caco-2) cell layers has been investigated. In Na(+)-containing solutions, net absorptive flux of beta-alanine from apical-to-basal surfaces is small or absent, despite Na(+)-dependent intracellular beta-alanine accumulation across both apical and basal surfaces. Upon apical acidification(More)
The mucosal surface pH of rat small intestine was measured in vivo. The surface pH in the normal jejunum was 6.20 +/- 0.02 (67) and 7.00 +/- 0.05 (5) in the ileum. Escherichia coli STa toxin induced a rapid and reversible alkalinization of both jejunal and ileal mucosae to a pH of 6.91 +/- 0.08 (10) and 7.67 +/- 0.06 (5) respectively. The synthetic ST(More)
The polarised nature of the increase in paracellular permeability induced by Ca(2+)-chelation with EGTA was investigated in several cultured epithelial cell lines. In strain I MDCK cells (canine kidney cells), a marked decrease (> 90%) in transepithelial electrical resistance (RT) and increase in mannitol and inulin permeabilities were only observed after(More)
Exposure to metals, particularly lead, remains a widespread issue that is associated with historical and current industrial practices. Whereas the toxic properties of metals are well described, exposure to metals per se is only one of many factors contributing to elevated blood metal concentrations and their consequent health effects in humans. The absorbed(More)
The mode of action of carbachol in stimulation of transepithelial Cl- secretion in intact human intestinal T84 epithelial monolayers has been investigated in order to determine whether a DIDS-insensitive exit pathway (via CFTR) coexists with a DIDS-sensitive exit pathway at the apical membrane. Carbachol stimulates a transient inward Isc due to Cl-(More)
The nature of polycation-induced change in transepithelial permeability was investigated in strains I (tight) and II (leaky) MDCK epithelial monolayers. Apical exposure to poly(L-lysine) (PLL, mol. wt. (MW) approximately 20,000) induced a dose-dependent increase in transepithelial conductance (GT) in both strains which correlated with increasing(More)
Previously, absorption of L-proline across the apical membrane of the intestinal enterocyte has been attributed to transport via the Na(+)-dependent Imino system. However, net (absorptive) transport of proline across intact Caco-2 cell monolayers was enhanced by acidification of the apical environment, under both Na(+)-containing and Na(+)-free conditions.(More)
Incorporation of a ligand into polyvinylchloride allows the production of ion selective electrodes that are soft-bodied and disposable. With features make them especially suitable for clinical, particularly gastroenterological, investigations. We report here on the construction of a combined reference and pH electrode suitable for use at jejunal biopsy.(More)