Effects of heavy metal ions on the electrical properties of mucous epithelial cells in the newt stomach.
Zinc ion, Cu2+ and Cd2+ at 10(-4) M or lower concentrations caused a marked decrease in the membrane potential of mucous epithelial cells in the isolated newt stomach without appreciable change in the effective membrane resistance and electrical coupling ratio. Cysteine and acetylpenicillamine antagonized the action of these ions. These ions as well as ouabain blocked the hyperpolarization of membrane due to an increase in intracellular Na+. The effect of the ions on the relationship between external K+-concentration and membrane potential was similar to that of ouabain. Discussion is made on the possibility that the ions inhibit active ion transport by combining with a SH-group of the cell membrane and, thus, bring about a decrease in membrane potential.
D000818:Animals; D003545:Cysteine / Q000494:pharmacology; D004553:Electric Conductivity; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects*; D008670:Metals / Q000494:pharmacology*; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D012455:Salamandridae
D008670:Metals; D010396:Penicillamine; D003545:Cysteine