title: Lead transport in IEC-6 intestinal epithelial cells.
abstract: This study evaluated the use of IEC-6 cells as a model for studying lead (Pb) transport by intestinal epithelial cells (IECs) and examined potential transport mechanisms for Pb uptake and extrusion. Pb accumulation in IEC-6 cells exposed to 5 and 10 microM Pb for up to 60 min was time- and dose-dependent. Reduction of incubation temperature significantly reduced the total cellular Pb content of IEC-6 cells. Simultaneous exposed of cells to zinc (Zn) and Pb resulted in decreased total cellular Pb contents compared to total cellular Pb contents of cells exposed to Pb only. IEC-6 cells treated with ouabain (1 mM) or sodium azide (1 mM) and 5 microM Pb accumulated more Pb than cells exposed to Pb only. Cells treated with p-chloromercuribenzensulfonic acid (50 microM), p-chloromercuribenzoic acid (50 microM), or iodoacetimide (50 microM) accumulated less Pb than cells treated with Pb only. We conclude that Pb uptake by IEC-6 cells depends on the extracellular Pb concentration. Our data suggest that the mechanism of Pb uptake by IECs is complex, and that Pb transport in IEC-6 cells is time- and temperature-dependent, involves sulfhydryl groups, and is decreased by the presence of Zn. Extrusion of Pb is at least partially dependent on metabolic energy.
authors.affiliation: Department of Veterinary Anatomy and Public Health, Texas A&M University, College Station 77843, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Dekaney
authors.forename: E D
authors.initials: ED
authors.lastname: Harris
authors.forename: G R
authors.initials: GR
authors.lastname: Bratton
authors.forename: L A
authors.initials: LA
authors.lastname: Jaeger
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002460:Cell Line; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D007854:Lead / Q000493:pharmacokinetics*; D051381:Rats; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D013696:Temperature; D015032:Zinc / Q000493:pharmacokinetics
chemical_list: D013438:Sulfhydryl Compounds; D007854:Lead; D015032:Zinc