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Journal article

Chloride secretion induced by mercury and cadmium: Action sites and mechanisms

Authors list: Böhme, Martin; Diener, Martin; Rummel, Walter

Publication year: 1992

Pages: 295-301

Journal: Toxicology and Applied Pharmacology

Volume number: 114

Issue number: 2

ISSN: 0041-008X

DOI Link: https://doi.org/10.1016/0041-008X(92)90080-C

Publisher: Elsevier

Abstract:

The actions of two mercury compounds, HgCl₂ and methyl mercury chloride (MeHg), and of CdCl₂ on the epithelium of the rat colon were studied with the whole-cell patch-clamp technique and the Ussing chamber. MeHg (50 μm) induced an increase of membrane outward current (I_out) in enterocytes of isolated crypts patched from the basolateral side. This action was inhibited by a Cl⁻ channel blocker and a K⁺ channel blocker, indicating an increase of both the Cl⁻ and the K⁺ conductance. In contrast, HgCl₂ (50 μm) did not affect I_out, whereas CdCl₂ (50 μm) decreased it slightly. In mucosal preparations all three compounds induced a concentration-dependent increase in shortcircuit current (I_sc) when administered to the serosal, i.e., contraluminal side. Sensitivity to chloride transport blockers and anion replacement experiments revealed that the increase in I_sc represented Cl⁻ secretion. In contrast to the actions of luminally applied mercury compounds, the increase of tissue conductance (G_t) was only small. Tetrodotoxin and indomethacin suppressed the effect of the metal compounds on I_sc and G_t, while atropine diminished it only partly. This indicates that the secretory action of these heavy metals has not only a direct effect on epithelial cells but is also mediated by prostaglandins and cholinergic and noncholinergic neurons.

Authors/Editors

- Uni.-Prof. Dr. Martin Heinz Diener

Citation Styles

Harvard Citation style: Böhme, M., Diener, M. and Rummel, W. (1992) Chloride secretion induced by mercury and cadmium: Action sites and mechanisms, Toxicology and Applied Pharmacology, 114(2), pp. 295-301. https://doi.org/10.1016/0041-008X(92)90080-C

APA Citation style: Böhme, M., Diener, M., & Rummel, W. (1992). Chloride secretion induced by mercury and cadmium: Action sites and mechanisms. Toxicology and Applied Pharmacology. 114(2), 295-301. https://doi.org/10.1016/0041-008X(92)90080-C