Epithelial intestine, characterization

INTESTINE Characterization of a membrane potassium ion conductance in intestinal secretory cells using whole cell patch-clamp and calcium-sensitive dye techniques, 192, 309 isolation of intestinal epithelial cells and evaluation of transport functions, 192, 324 isolation of enterocyte membranes, 192, 341 established intestinal cell lines as model systems for electrolyte transport studies, 192, 354 sodium chloride transport pathways in intestinal membrane vesicles, 192, 389 advantages and limitations of vesicles for the characterization and the kinetic analysis of transport systems, 192, 409 isolation and reconstitution of the sodium-de-pendent glucose transporter, 192, 438 calcium transport by intestinal epithelial cell basolateral membrane, 192, 448 electrical measurements in large intestine (including cecum, colon, rectum), 192, 459... 

Additional epithelial aqueous pathways of significantly smaller radius (<3 A) have also been documented utilizing both equivalent pore and circuit theory [25], These pathways may correspond to specific channels through lipid membranes as opposed to paracellular pathways. Osmotically activated ion channels [35] and even specific water channels [36] have been characterized in renal epithelia. In intestinal epithelia, mucosal chloride channels have been studied in secreting crypt cells, and basolateral potassium channels in colonic epithelia serve cellular ion and volume homeostatic functions. 

Borchardt. Characterization of the human colon carcinoma cell line (Caco-2) as a model system for intestinal epithelial permeability, Gastroenterology 1989, 96, 736—749... 

Langer RC, Schaefer DA, Riggs MW Characterization of an intestinal epithelial cell receptor recognized by the Cryptosporidium parvum sporozoite ligand CSL. Infect Immun 2001 69 1661-1670. 

Figure 23.3 Drug transporters in the intestinal epithelial cells. PEPT1 is the most characterized transporter for intestinal drug absorption. The basolateral peptide transporter, which is not identified at the molecular level, also plays important roles. OATP-B, OCTN2 and MRP3 may be responsible for the intestinal absorption of some drugs. On the contrary, ABC transporters such as P-gp located at brush-border membranes mediated the efflux of drugs from intestinal epithelial cells, contributing to the low bioavailabihty of drugs such as the immunosuppressive agent, tacrolimus.

Figure 1. Acid and non-acid glycosphingolipids were prepared and characterized from different compartments of rat small intestine non-epithelial residue, total epithelial cells, and epithelial cells of different maturity (crypt, intermediate, and...

In our initial studies reported here of glycolipids of rat small intestine, preparative and structural methods were adapted to characterize epithelial and non-epithelial tissue and epithelial cells of different location and level of differentiation. The two compartments were distinctly different with core saccharides with GalNAc being restricted to non-epithelial cells while those... 

The intrinsic barrier of the gastrointestinal epithelium is characterized by intercellular junctions at the apical (luminal) side of differentiated epithelial cells, the so-called tight junctions (TJ), and the maintenance of epithelial integrity based on the balance between cellular proliferation and cell death, as described above. Barriers against drug absorption by the intracellular and paracellular routes, their modulation, and maintenance will be discussed in the following, with the focus on the intestinal epithelium. 

JAM-1 is a glycoprotein of the IgG superfamily of 43 kDa, one TMD, and two extracellular V-type Ig domains (Martin-Padura et al. 1998). The carboxy terminus is characterized by a PDZ-binding domain, which binds to the PDZ motif of ZO-1 (Hamazaki et al. 2002). Other members of the JAM family have been identified, such as JAM-4, which is expressed in renal glomerular and intestinal epithelial cells, where it was shown to induce Ca2 +-independent intercellular adhesion (Hirabayashi et al. 2003). JAM-1 is further connected to cytosolic... 

Just recently a series of other quaternized chitosan derivatives have been synthesized and characterized, namely, A,A-dimethyl, A-ethyl chitosan (DMEC) (Bayat et al. 2006), A-methyl, A,A-diethyl chitosan (DEMC) (Avadi et al. 2004) and A,A,A-triethyl chitosan (TEC) (Avadi et al. 2003). In a comprehensive study (Sadeghi et al. 2008a, b) the four quaternized derivatives of chitosan, trimethyl chitosan (TMC), diethylmethyl chitosan (DEMC), triethyl chitosan (TEC) and dimethylethyl chitosan (DMEC) with degree of substitution of approximately 50% were synthesized and their effect on the permeability of insulin across intestinal Caco-2 monolayers was studied and compared with chitosan both in free-soluble form and in nanoparticulate systems. Trans-epithelial electrical resistance (TEER) studies revealed that all four chitosan derivatives in free-soluble forms were able to decrease the TEER value in the following order TMC>DEMC>TEC = DMEC>chitosan, indicating their... 

Ohishi I, Hama Y (1992) Purification and characterization of heterologous component lls of botulinum C2 toxin. In Microbiol Immunol. 36 221 -9 Ohishi I, Iwasaki M, Sdkaguchi G. (1980) Purification and characterization of two components of botulinum 02 toxin. In Infect Immun. 30 668-73 Ohishi I, Miyake M (1985) Binding of the two components of 02 toxin to epithelial cells and brush borders of mouse intestine. In Infect Immun. 48 769-75 Ohishi I, Tsuyama S (1986) ADP-ribosylation of nonmuscle actin with component I of 02 toxin. In Biochem Biophys Res Comm. 136 802-6 Ohishi I, Yanagimoto A (1992) Visualizations of binding and internalization of two nonlinked protein components of botulinum 02 toxin in tissue culture cells. In Infect Immun. 60 4648-55... 

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