title: Dose Effects of Apical versus Basolateral Zinc Supplementation on Epithelial Resistance, Viability, and Metallothionein Expression in Two Intestinal Epithelial Cell Lines.
abstract: Zinc supplementation is used to reduce diarrhea incidence in piglets and it has been shown in vitro that the antisecretory effects are maximal after basolateral zinc application. To examine whether the application site and dose of zinc also influence passive ion permeability and viability, porcine (IPEC-J2) and human (Caco-2) intestinal epithelial cells were treated with increasing zinc concentrations (0-200 μM) at either the apical or basolateral side. Transepithelial electrical resistance and viability decreased and expression of metallothionein and the efflux zinc transporter 1 increased most prominently when zinc was added in high concentrations at the basolateral side of IPEC-J2 cells. Zinc transporter 4, a zinc importer, was not affected. Heat shock protein 70 mRNA expression increased only after basolateral addition of 200 μM zinc in IPEC-J2 cells. Thus, zinc can elicit toxic effects especially when added at the basolateral side, with IPEC-J2 cells being more susceptible than Caco-2 cells.
authors.affiliation: Department of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, 14163, Berlin, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Lodemann
authors.affiliation: Department of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, 14163, Berlin, Germany.
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Gefeller
authors.affiliation: Department of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, 14163, Berlin, Germany.
authors.forename: Jörg R
authors.initials: JR
authors.lastname: Aschenbach
authors.affiliation: Department of Veterinary Medicine, Institute of Veterinary Physiology, Freie Universität Berlin, 14163, Berlin, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Martens
authors.affiliation: Department of Veterinary Medicine, Institute of Veterinary Biochemistry, Freie Universität Berlin, 14163, Berlin, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Einspanier
authors.affiliation: Department of Veterinary Medicine, Institute of Veterinary Biochemistry, Freie Universität Berlin, 14163, Berlin, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Bondzio
keywords: Heat Shock Protein; Intestinal Epithelial Cell; Metallothionein; Transepithelial Electrical Resistance; Viability; Zinc; Zinc Transporter