Uptake by intestine

Other kinetic parameters can be specified as a function of system capacity. For example, from information on lumenal volume (V), kinetic uptake by intestinal epithelia can be defined as a clearance (Cl) from the lumenal compartment [43],... 

Yet another potential pathway for NTBI uptake by intestinal and erythroid cells has been proposed involving integrins and mobilferrin (Conrad and Umbreit, 1993 Conrad et ah, 1994), although its physiological relevence remains uncertain. 

Dietary fats are required for carotenoid uptake by intestinal cells. Fats have an important role in the continuation of the process of carotenoid absorption, because the human intestine is incapable of secreting significant quantities of chylomicrons into the bloodstream in the absence of fats (Ornelas-Paz and others 2008b). Some studies have suggested that at least 5 g/day of dietary fat are required for suitable (3-carotene absorption (West and Castenmiller 1998), whereas others suggested the consumption... 

B. Dietary lipids are processed by several pancreatic lipases, whose actions facilitate uptake by intestinal epithelial cells (enterocytes). 

Colman, N., Hettiarachchy, N. and Herbert, V. 1981. Detection of a milk factor that facilitates folate uptake by intestinal cells. Science 211, 1427-1429. 

Oomen AG, Tolls J, Kruidenier M, Bosgra SSD, Sips A, Groten JP. 2001. Availability of polychlorinated biphenyls (PCBs) and lindane for uptake by intestinal Caco-2 cells. Environ Health Perspect 109 731-737. 

FEXOFENADINE GRAPEFRUIT JUICE Possibly 1 efficacy i absorption possibly by affecting P-gp and direct inhibition of uptake by intestinal OATP-1A2 Clinical significance unclear. No dinically significant changes in ECG parameters were observed in one study... 

Niclosamide blocks glucose uptake by intestinal tapeworms. It may cause some mild gastrointestinal symptoms. 

Despite the existing evidence attesting to the safety of dietary astaxanthin, little is known about the bioavailability and metabolism of this carotenoid in humans. Several steps are involved in the assimilation of carotenoids by mammals, including transfer from the food matrix, transfer to lipid micelles in the small intestine, uptake by intestinal mucosal cells, transport to the lymph system, and eventually, deposition of the carotenoid or its metabolites in specific tissues. " A number of factors can influence the progression of these steps, including the nature of the food matrix, " the structure of the carotenoid (including potential esterification and the nature of its isomeric composition), the presence of other carotenoids, " and the amount and types of lipids in the diet. Overall, human metabolism of astaxanthin should be somewhat similar to that of the other xanthophylls, but subtle differences are expected. 

Grapefruit juice also diminished the AUC of fexofenadine variably among individuals. This decreased oral bioavailability is likely a contribution of direct inhibition of its uptake by intestinal OATP-A (Dresser et al., 2005). 

FIG. 1. D-Glucose uptake by intestinal brush border membranes and the effect of osmolality. Brush border membranes (110 /ig protein) were incubated for various times at 2S°C with 200 fiM [ H]glucose, ISO mM NaSCN, 100 mM mannitol, 1 mM Hepes/Tris buffer, pH 7J, in 40 /il. The vesicular uptake was terminated by a 2S-fold dilution with ice-cold stop solution consisting of 100 mAf mannitol, ISO mM NaCl, 0.2 mM phlorizin, and SS Mg02 in 10 mM Hepes/Tris buffer, pH 7.S. The uptake was measured in the presence of 300 mM o-cellobiose (closed circles) or in its absence (open circles). 

Feinroth M, Feinroth MV, Berlyne GM (1982) Aluminum absorption in the rat everted gut sac. Miner Electrolyte Metabol 8 29-35 Fernandez Mendez MJ, Fell GS, Brock JH (1991) Aluminium uptake by intestinal cells effect of iron status and precomplexation. Nephrol Dial Transplant 6 672-674... 

Paton, W. D. M., and Rang, H. P. (1965). The uptake of atropine and related drags by intestinal smooth muscle of the guinea pig in relation to acetylcholine receptors. Proc. R. Soc. Lond. [Biot.] 163 1-44. 

Production of Mucosal Damage 2.3.1.2.1 Cell culture Stimulated neutrophils are known to be cytotoxic to cells in vitro (Dull et al., 1987 Dallegri et al., 1990 Grisham et al., 1990b). Several in vitro systems have been used to demonstrate oxidative damage to intestinal cells. Xanthine/XO increased Cr release and decreased [ H]thymidine uptake by IEC-18 small intestinal epithelial cell monolayers in a dose-dependent manner (Ma et al., 1991). Rat enterocytes show decreased trypan blue exclusion and increased protein release when incubated with neutrophils stimulated... 

H Yuasa, D Fleisher, GL Amidon. Noncompetitive inhibition of cephradine uptake by enalapril in rabbit intestinal brush-border membrane vesicles An enalapril specific inhibitory binding site on the peptide carrier. J Pharmacol Exp Ther 269 1107-1111, 1994. 

Selective Uptake of All-trans P-C versus Its cis Isomers by Intestinal Cells...372... 

In summary, Caco-2 cells studies strongly suggest that carotenoids interact with each other at the level of cellular uptake by the enterocyte. This phenomenon has been explained by the fact that the uptake of several carotenoids involves, at least in part, the same intestinal membrane transporter the scavenger receptor class B type ISR-BI (Reboul et al. 2005, van Bennekum et al. 2005, Moussa et al. 2008). 

Traber, M. G. et al. (1990). Vitamin E uptake by human intestinal cells during lipolysis in vitro. Gastroenterology 98(1) 96-103. 

Trotter, P. J. et al. (1996). Fatty acid uptake by Caco-2 human intestinal cells. J. Lipid Res. 37(2) 336-346. 

I. F., MacKay, M., Proline uptake by monolayers of human intestinal absorptive (Caco-2) cells in vitro, Biochim. Biophys. Acta 1992, 1104, 283-292. 

Kitagawa, S., J. Takeda, and S. Sato. pH-dependent inhibitory effects of angiotensin-converting enzyme inhibitors on cefroxadine uptake by rabbit small intestinal brush-border membrane vesicles and their relationship with hydrophobicity and the ratio of zwitterionic species. Biol. Pharm. Bull. 1999, 22, 721-724. 

The uptake of radiocerium by intestinal lining cells is not unique but may be expected to occur in similar chemical compounds that form colloids or large complexes within the intestine (Sullivan, 1966). Macromolecules are known to be easily absorbed by the intestinal cells of newborn animals through the process of pinocytosis (Clark, 1959). Polyvinylpyrrolidone (PVP) has been shown to be taken into the intestinal cells of rats less than 18 days old (Clarke and Hardy, 1969). 

After cell uptake, provitamin A carotenoids are readily bioconverted to retinal by intestinal cells, although some bioconversion of carotenoids can take place in the liver (West and Castenmiller 1998). The retinal can be reversibly reduced to retinol or... 

---