An electroneutral anion exchange mechanism is present in brush border membranes isolated from eel kidney. Vilella, S., L. Ingrosso, V. Zonno, T. Schettino, and C. Storelli. Laboratorio di Fisiologia generale, Dipartimento di Biologia, Universit[grave]a di Lecce. Via Provinciale Monteroni, 73100 Lecce, ITALIA
APStracts 3:0434R, 1996.
The mechanism of bicarbonate translocation across the luminal membrane of the eel (Anguilla anguilla ) kidney tubular cells was studied by monitoring the uptake of H14CO3- into isolated brush border membrane vesicles. Results indicate that the presence of a transmembrane outwardly directed Cl- gradient was able to transiently accumulate H14CO3- into the vesicular space, while neither an inwardly directed sodium gradient nor a transmembrane electrical potential gradient (inside positive) were able to stimulate the H14CO3- influx. This anion-dependent H14CO3- uptake was inhibited by 4,4' -diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) suggesting that an anion exchanger was present in the brush border membrane vesicles.

Received 21 February 1996; accepted in final form 30 October
1996.
APS Manuscript Number R107-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996