Identification of a V-type proton pump in the outer mantle epithelium of Anodonta cygnea

• Tipo: Artigo em Revista Científica Internacional
• Data: 1999

Autores

da Costa, AR (Autor) Outra; Oliveira, PF (Autor) Outra; Barrias, C (Autor) Outra; Ferreira, HG (Autor) Outra

Revista

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Título: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY

Vol. 123

Páginas: 337-342

ISSN: 1095-6433

Indexação

ISI Web of Knowledge - 8 Citações

Scopus - 10 Citações

Outras Informações

ID Authenticus: P-001-3PR

DOI: 10.1016/s1095-6433(99)00069-0

Abstract (EN): The dissected outer mantle epithelium (OME) of Anodonta cygnea, when mounted in Ussing type chambers, generated a spontaneous potential difference of 22.0 +/- 12.6 mV and, when short-circuited, a positive current (I-sc) of 30.0 +/- 11 mu A/cm(2) towards the shell side and a conductance of 1.1 +/- 0.4 mS/cm(2). When in contact with the shell side, Bafilomycin A(1) and Concanamycin A, specific inhibitors of V-proton pumps, induced 90% inhibition of I-sc in 5 and 35 min, respectively. They had no effect in the current from the hemolymph side. Both drugs induced a dramatic fall in conductance from the shell side. Tributyltin oxide (TBTO) inhibited 90% of the I-sc in 3 min and induced a fall in conductance only from the shell side. Two observations suggest a direct effect on the proton pump: it was effective only from the shell side and the time course of the effect was identical to that of Bafilomicyn A(1). Dicyclohexycarbodiimide (DCCD) and N-ethylmaleimide (NEM) inhibited I-sc from both sides but very slowly and there was a delay of the effect from the hemolymph side in relation to the shell side. Taken together, the results suggest the presence of a V-type proton pump located at the apical (shell side) barrier of the OME.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6