Effect of mercuric chloride on electrical parameters and anion fluxes in the toad skin.
Comp Biochem Physiol C Toxicol Pharmacol
; 140(1): 21-7, 2005 Jan.
Article
em En
| MEDLINE
| ID: mdl-15792619
The amphibian skin, widely used for studying the transepithelial passage of electrolytes, exhibits anion pathways relatively specific for Cl(-). We studied the effect of HgCl(2), 1.0 x 10(-4) M on its electrical parameters and unidirectional anion fluxes. In the presence of Cl(-), the transepithelial conductance (G) of the isolated skin of the Bufo arenarum toad increased considerably following exposure to HgCl(2), whereas short-circuit current (SCC)--reflecting transepithelial Na(+) transport-underwent only slight stimulation. Following the blockade of Na(+) intake by amiloride, 1.0 x 10(-4) M, the removal of Cl(-) from the solution bathing the epidermal border of the skin brought about a decrease in G, and gave rise to a gradient-induced SCC (SCCg) consistent with transepithelial passage of Cl(-) along its gradient. Addition of mercaptoethanol, 5.0 x 10(-3) M to the bath containing Hg(2+) fully reversed these effects. The increase in G was accompanied by an increase in the unidirectional (epidermal to dermal) fluxes of (36)Cl(-) and (131)I(-), and a decrease in the passage of (99m)TcO(4)(-). These results show the effects of HgCl(2) to be similar to those of theophylline, although exhibiting a different selectivity. Our data suggest that anion passage following exposure to HgCl(2) is, like that stimulated by theophylline, predominantly if not exclusively transcellular, and does not involve a significant opening of the tight junctions.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Absorção Cutânea
/
Bufo arenarum
/
Proteínas de Transporte de Ânions
/
Condutividade Elétrica
/
Cloreto de Mercúrio
Limite:
Animals
Idioma:
En
Revista:
Comp Biochem Physiol C Toxicol Pharmacol
Assunto da revista:
FARMACOLOGIA
/
TOXICOLOGIA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Estados Unidos