US EPA

4978106 

Journal Article 

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

Boehme, M; Diener, M; Rummel, W 

1992 

1 

Toxicology and Applied Pharmacology
ISSN: 0041-008X
EISSN: 1096-0333 

114 

2 

295-301 

English 

BIOSIS COPYRIGHT: BIOL ABS. 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 (50muM) induced an increase of membrane outward current (Iout) 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 muM) did not affect Iout, whereas CdCl2 (50 muM) decreased it slightly. In mucosal preparations all three compounds induced a concentration-dependent increase in short-circuit current (Isc) when administered to the serosal, i.e., contraluminal side. Sensitivity to chloride transport blockers and anion replacement experiments revealed that the increase in Isc represented Cl- secretion. In contrast to the actions of luminally applied mercury compounds, the increase of tissue