Epithelial uptake

Moestrup, S. K. 2006. New insights into carrier binding and epithelial uptake of the erythropoietic nutrients cobalamin and folate. CurrOpin Hematol, 13, 119-23. 

Smith LL, Wyatt I, Cohen GM (1982) The accumulation of diamines and polyamines into rat lung slices. Biochem Pharmacol 31 3029-3033. doi 10.1016/0006-2952(82)90075-2 Smith LL, Lewis CP, Wyatt I, Cohen GM (1990) The importance of epithelial uptake systems in lung toxicity. Environ Health Perspect 85 25-30... 

A different line of evidence for the idea that failure to remove particles from the lung leads to epithelial uptake comes from experiments using tracheal explants. Tracheal explants are, for practical purposes, free of inflammatory cells. If such explants are briefly exposed to a suspension of dust particles, the particles... 

The limited data reporting uptake as a function of time suggest that alveolar epithelial uptake is probably faster than bronchiolar epithelial uptake. Watson and Brain found 5-nm-iron oxide particles within type I cells 1 hr after a 3-hr-inhalation exposure (73). Chrysotile fibers were visible within type I cells at the end of a 1 hr high-level inhalation exposure (55) by 5 hr after exposure, some fibers had been U anslocated to the interstitium. Carbon, latex, and sihca particles have also been shown in type I cells within 24 hr of intratracheal or inhalation exposure (64,76,77). 

The increase in lymph node burden seen with ultrafine titanium dioxide has also been cited as evidence of increased interstitial transport of small particles (49,91). The problem with this line of reasoning is that, although, in one sense, it is true by definition, increased lymph node burdens tell nothing of the route by which the particles reached the lymph nodes certainly lymph node burdens provide no direct information about epithelial uptake and transport. 

Keeling B, Hobson J, Churg A. Effects of cigarette smoke on tracheal epithelial uptake of non-asbestos mineral particles in organ culture. Am J Respir Cell Mol Biol 1993 9 335 340. 

The bumetanide-sensitive Na+, K+, 2CF cotransporter (NKCC) mediates the electroneutral uptake of chloride across epithelial cell membranes and is found in both absorptive and secretory epithelia (airways, salivary gland). NKCC exists in two isoforms, the secretory isoform NKCC1, and the absorptive isoform NKCC. 

In many epithelia Cl is transported transcellularly. Cl is taken up by secondary or tertiary active processes such as Na 2Cl K -cotransport, Na Cl -cotransport, HCOJ-Cl -exchange and other systems across one cell membrane and leaves the epithelial cell across the other membrane via Cl -channels. The driving force for Cl -exit is provided by the Cl -uptake mechanism. The Cl -activity, unlike that in excitable cells, is clearly above the Nernst potential [15,16], and the driving force for Cl -exit amounts to some 2(f-40mV. 

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... 

Lomejad-Schafer, MR, Lambert, C, Breithaupt, DE, Biesalski, HK, and Frank, J, 2007. Solubility, uptake and biocompatibility of lutein and zeaxanthin delivered to cultured human retinal pigment epithelial cells in tween40 micelles. Eur JNutr 46, 79-86. 

Hu, M. and R. Borchardt. Transport of a large neutral amino acid in a human intestinal epithelial cell line (Caco-2) uptake and efflux of phenylalanine., Biochim. Biophys. Acta 1992, 3335, 233-244... 

The transporter-mediated uptake of drugs into epithelial cells is emerging as a new trend in biopharmaceutics [6]. Utilization of the intestinal epithelial transporters to facilitate the absorption of drugs or prodrugs appears to be an attractive delivery approach. The purpose of this chapter is to describe the pharmaceutical and medicinal relevances of intestinal transporters. This will provide new knowledge for strategies to enhance intestinal absorption of drugs. 

Homof M, de la FM, Hallikainen M, Tammi RH, Urtti A (2008) Low molecular weight hyaluronan shielding of DNA/PEI polyplexes facilitates CD44 receptor mediated uptake in human corneal epithelial cells. J Gene Med 10 70-80... 

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