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

• Type: Article in International Scientific Journal
• Date: 1999

Authors

da Costa, AR (Author) Other; Oliveira, PF (Author) Other; Barrias, C (Author) Other; Ferreira, HG (Author) Other

Journal

The Journal is awaiting validation by the Administrative Services.

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

Vol. 123

Pages: 337-342

ISSN: 1095-6433

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 10 Citations

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6