Despite significant advances in the characterization of tight junction (TJ) proteins, little is known about how molecular changes relate to function due primarily limitations conventional paracellular probes. To address this, pathway Caco-2 and T84 cell lines was profiled by measuring permeabilities 24 polyethylene glycols (PEG) increasing radius (3.5–7.4 Å) analyzed mass spectrometry. When combined with a sieving model, these data provided quantitative descriptors under control conditions...

Saccharomyces boulardii, a yeast that was isolated from fruit in Indochina, has been used as remedy for diarrhea since 1950 and is now commercially available treatment throughout Europe, Africa, South America. Though initially classified separate species of Saccharomyces, recent publications have shown the genome S. boulardii so similar to cerevisiae two should be conspecific. This raises question distinguishing molecular phenotypic characteristics present make it perform more effectively...

Intestinal drug efflux mediated by P-glycoprotein and other ABC transporters is widely accepted as a reason for low or variable oral absorption. However, little known about species regional differences in so the functional predictive relevance of observations made cell models such Caco-2 uncertain. The aim this study was to define kinetics rat human intestinal tissues vitro using "reference" substrates digoxin vinblastine. expression role transport these compounds also investigated....

The influence of secretory transporters on intestinal permeability characteristics the H2 receptor antagonists ranitidine and cimetidine was studied in Caco-2 monolayers rat mucosa mounted Ussing chambers. Both drugs exhibited vectorial transport across ileum with significantly greater (2-4-fold) serosal-to-mucosal than mucosal-to-serosal direction, indicative net mucosal secretion. Mucosal secretion also observed distal colon, although to a lesser degree. Ileal concentration dependent...

The present study has investigated whether fatty acids directly influence peptide release from enteroendocrine cells using STC‐1, a mouse intestinal endocrine tumour cell line, previously shown to cholecystokinin (CCK) in response other physiological stimuli. Fatty elicited chain length‐ and dose‐dependent stimulation of CCK secretion. Dodecanoic acid (C12) was most effective, producing up 5‐fold increase with less than ten carbon atoms did not length dependence these effects mimics closely...

Transporter proteins expressed in the gastrointestinal tract play a major role oral absorption of some drugs, and their involvement may lead to drug-drug interaction (DDI) susceptibility when given combination with drugs known inhibit gut wall transporters. Anticipating such liabilities predicting magnitude impact transporter on drug DDIs requires quantification expression human intestine, linking these data obtained through vitro experiments. A quantitative targeted absolute proteomic...

Over the last 5 years quantification of transporter-protein absolute abundances has dramatically increased in parallel to expanded use vitro–in vivo extrapolation (IVIVE) and physiologically based pharmacokinetics (PBPK)-linked models, for decision-making pharmaceutical company drug development pipelines regulatory submissions. Although several research groups have developed laboratory-specific proteomic workflows, it is unclear if large range reported variability founded on true...

Information on the extent to which xenobiotics interact with P-glycoprotein (PGP) during transit through intestine is crucial in determining influence of PGP oral drug absorption. We have recently described a novel use isolated ileum from PGP-deficient mdr1a(−/−) mice resolve PGP- and non-PGP-dependent efflux provide definitive measure intrinsic permeability without recourse inhibitors (Stephens et al., 2002). The present study uses this approach investigate impact intestinal paclitaxel...

Background —Production of chemoattractant factors by the intestinal epithelium may contribute to mucosal infiltration inflammatory cells in bowel disease. Secretion α chemokine interleukin 8 (IL-8), a neutrophil chemoattractant, has been widely studied, but little is known about epithelial secretion β chemokines, which are preferentially involved recruiting monocytes. Aims —To investigate profiles and colonic cell lines their differential modulation interferon γ (IFN-γ), product activated T...

1 Fatty acid-induced cholecystokinin (CCK) secretion in humans and from the enteroendocrine cell line STC-1 depends critically on acyl chain length. 2 Therefore we have characterized relationship between length potency of fatty acid to induce CCK changes intracellular Ca2+ concentration ([Ca2+]i) two lines (STC-1 GLUTag). We found that was directly proportional its therefore inversely solubility. 3 In both types, rise [Ca2+]i response decanoic (C10), dodecanoic (C12) tetradecanoic (C14)...

Relative expression factors (REFs) are used to scale in vitro transporter kinetic data via vitro–in vivo extrapolation linked physiologically based pharmacokinetic (IVIVE-PBPK) models clinical observations. Primarily two techniques quantify protein available, immunoblotting and liquid chromatography–tandem mass spectrometry. Literature-collated REFs ranged from 0.4 5.1 1.1 90 for intestinal P-glycoprotein (P-gp) breast cancer resistance (BCRP), respectively. The impact of using human...

Chronic dietary K + loading stimulates an active secretory process in rat distal colon, which involves increase the macroscopic apical conductance of surface epithelial cells. In present study, abundance and characteristics channels constituting this enhanced were evaluated using patch clamp recording techniques.2. isolated non‐polarized cells, seen 9 90 (10%) cell‐attached patches cells from control animals, 247 437 (57%) ‐loaded with a significant ( P < 0.001 ) shift distribution...

The basolateral membrane of human colonic crypt cells contains Ca2+ and cAMP activated, Ba2+ blockable, low conductance (23 pS) K+ channels, which probably play an important part in intestinal Cl- secretion. This study has defined more clearly the conductive properties crypts using patch clamp recording techniques. High (138 channels were seen 25% patches (one or two per patch), significantly inhibited by addition 5 mM Ba2+, 1 quinidine 20 tetraethylammonium chloride (TEA) to cytosolic side...

ABSTRACT Escherichia coli strain Nissle 1917 has been widely used as a probiotic for the treatment of inflammatory bowel disorders and shown to have immunomodulatory effects. expresses K5 capsule, expression which often is associated with extraintestinal urinary tract isolates E. . In this paper, we investigate role capsule in mediating interactions between intestinal epithelial cells. We show that loss significantly reduced level monocyte chemoattractant protein 1 (MCP-1), RANTES,...

Intestinal xenobiotic transporters are a significant barrier to the absorption of many orally administered drugs. P‐glycoprotein (PGP) is best known, but several others, including members multidrug resistance‐associated protein (MRP) family, also expressed. Definitive information on their precise effect intestinal drug permeability scarce due lack specific inhibitors and difficulty studying non‐PGP activity in presence high PGP expression. We have investigated vitro use tissues from knockout...

Using the functionally differentiated colonic cell line, HT29-19A, we have examined sites at which inhibitory G-proteins mediate antisecretory actions of somatostatin (SST) and alpha 2-adrenergic agonist, clonidine (CLON) epithelial level. Both agents caused a dose-dependent inhibition (EC50:SST 35 nM; CLON 225 nM) Cl- secretion (assessed by changes in short circuit current) activated cAMP-mediated agonists, PGE2 cholera toxin. Inhibition was accompanied reduction intracellular cAMP...

In rabbit ileum in vitro Clostridium difficile toxin (200 microliter crude extract) almost abolished net Na absorption, by decreasing mucosa to serosa flux, and induced Cl secretion increasing the flux. These flux changes were when there was no visible histological damage mucosa. The did not influence adenylate or guanylate cyclase activity a plasma membrane fraction of isolated enterocytes nor it affect cAMP concentrations intact pre-incubated with toxin. responses prevented removing...

Cisapride is a synthetic drug which binds, in vitro, to type 2 serotonin receptors. We examined the influence of and cisapride on ion transport across intestinal mucosa vitro studied effect response serotonin. Segments ileum male Sprague-Dawley rats were stripped muscle layers mounted flux chambers. The addition (10(-8) 10(-4) M) serosal aspect caused rapid, dose-dependent rise short circuit current transmural potential difference. alone (5 X 10(-5) M), when added mucosal surfaces, had no...