title: Cationic currents induced by Clostridium perfringens type A enterotoxin in human intestinal CaCO-2 cells.
abstract: Clostridium perfringens type A produces an enterotoxin that induces diarrhoea experimentally in man and animals. The enterotoxin causes increased membrane permeability in susceptible cells which is thought to be due to pore formation in the host cell membrane. The effect of purified C. perfringens enterotoxin on intact intestinal CaCO-2 monolayers was examined in Ussing chambers and on single cells by whole-cell patch clamp. Mucosal application of C. perfringens enterotoxin resulted in prompt increases in short-circuit current coupled with a reduction in transepithelial resistance consistent with movement of sodium and other cations smaller than diethanolamine from mucosa to serosa. These changes were independent of extracellular calcium. Increases in short-circuit current were also observed in the apical membranes of CaCO-2 monolayers permeabilised across the basolateral membrane with nystatin. Currents were blocked by subsequent exposure to mucosal barium and zinc. Zinc also prevented the development of the current increases in apical membranes. Cationic currents were also observed following exposure of single CaCO-2 cells in whole-cell patch clamp recordings. These data indicate that C. perfringens enterotoxin is able to form cation permeant pores in the apical membrane of human intestinal CaCO-2 epithelia and the increases in short-circuit current can be prevented by pre-exposure to zinc ions.
authors.affiliation: Department of Pharmacy, University of Brighton, Lewes Road, Brighton, East Sussex BN2 4GJ.
authors.forename: S P
authors.initials: SP
authors.lastname: Hardy
authors.affiliation: Department of Pharmacy, University of Brighton, Lewes Road, Brighton, East Sussex BN2 4GJ.
authors.forename: M
authors.initials: M
authors.lastname: Denmead
authors.affiliation: Department of Pharmacy, University of Brighton, Lewes Road, Brighton, East Sussex BN2 4GJ.
authors.forename: N
authors.initials: N
authors.lastname: Parekh
authors.affiliation: Department of Pharmacology, Microbiology and Food Hygiene, Norwegian College of Veterinary Medicine, PO Box 8146, Oslo, Norway.
authors.forename: P E
authors.initials: PE
authors.lastname: Granum
mesh_terms: D018938:Caco-2 Cells / Q000187:drug effects* / Q000378:metabolism; D002412:Cations / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects; D003016:Clostridium perfringens / Q000378:metabolism*; D004594:Electrophysiology; D004768:Enterotoxins / Q000494:pharmacology*; D006801:Humans; D007473:Ion Channels / Q000187:drug effects; D017136:Ion Transport / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D015032:Zinc / Q000494:pharmacology
chemical_list: D002412:Cations; D004768:Enterotoxins; D007473:Ion Channels; C035598:enterotoxin, Clostridium; D015032:Zinc