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Title: Characterization of zinc (Zn) transport across Caco-2 cell monolayers

Characterization of zinc (Zn) transport across Caco-2 cell monolayers Colonic carcinoma Caco-2 cells grown as a monolayer exhibit many of the characteristics of the small intestine including inducibility of metallothionein by Zn. The authors have now characterized the transport of Zn across confluent, 14 day in vitro Caco-2 monolayers grown on polycarbonate support membranes. Both uptake and transport across the cells were linear for at least 10 min. Zn cell uptake in the mucosa-to-serosa (m-s) direction was saturable, with a K{sub t} = 23.8 {plus minus} 7.8 {mu}M. J{sub max} was 0.46 {plus minus} 0.08 {mu}mol/cm{sup 2} {times} 10 min. Transcellular passage was concentration dependent. In the (s-m) direction, the K{sub t} of Zn cell uptake was 59 {plus minus} 13 {mu}M and that of the transcellular transport was 103 {plus minus} 53 {mu}M. Cell uptake J{sub max} was 0.98 {plus minus} 0.11 {mu}mol/cm{sup 2} {times} 10 min, and transcellular transport J{sub max} was 2.90 {plus minus} 0.47 {mu}mol/cm{sup 2} {times} 10 min. Low molecular weight ligands (histidine, cysteine, proline or glutathione at 1 mM each), added to the mucosal side, did not alter Zn cell uptake or transmembrane passage. Potential transport inhibitors such as ouabain or vanadate, or metabolic inhibitors also had no effect. Zn transport and cell more » uptake by Caco-2 cells are kinetically comparable to those of in vivo systems and could serve as a valid model for Zn absorption studies. « less
Authors: ; ;
Publication Date:
OSTI Identifier:OSTI ID: 5239861
Report Number(s):CONF-9104107--
Journal ID: ISSN 0892-6638; CODEN: FAJOE
Resource Type:Conference
Resource Relation:Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States); Journal Volume: 5:5; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991
Country of Publication:United States
Language:English
Subject: 63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; ZINC; MEMBRANE TRANSPORT; CARCINOMAS; INTESTINAL ABSORPTION; LIGANDS; METABOLISM; METALLOTHIONEIN; SMALL INTESTINE; TUMOR CELLS; ABSORPTION; ANIMAL CELLS; BODY; DIGESTIVE SYSTEM; DISEASES; ELEMENTS; GASTROINTESTINAL TRACT; INTESTINES; METALLOPROTEINS; METALS; NEOPLASMS; ORGANIC COMPOUNDS; ORGANS; PROTEINS; UPTAKE 560300* -- Chemicals Metabolism & Toxicology