HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Robson, L Articles by Hunter, M Search for Related Content PubMed PubMed Citation Articles by Robson, L Articles by Hunter, M

Department of Physiology, Medical School, Leeds University, UK.

1. This study investigated the effect of the anion, SCN-, on the conductive properties of single proximal tubule cells isolated from frog kidney. Ionic currents were measured using the conventional whole-cell patch clamp technique. 2. Addition of SCN- to the bath solution alone had a biphasic effect; there was an initial rapid rise, followed by a slower secondary increase, in both outward and inward conductances. However, when SCN- was added to the bath in the presence of pipette SCN-, such that the concentration gradient for movement of SCN- into the cell was abolished, only the fast changes in conductance were observed. 3. Cells did not discriminate between cations and anions under nominally K(+)-free control conditions. However, in the presence of intracellular SCN- cells became anion selective. Taken together with the increased conductance, this suggests activation of a Cl- channel (gSCN). 4. Niflumic acid, a Cl- channel blocker, inhibited gSCN in a dose-dependent manner, with a half-maximal blocking concentration (Ki) of 28 +/- 2.8 microM and a Hill coefficient of 1.2 +/- 0.3 (n = 6). 5. The activation of gSCN by intracellular SCN- was dose dependent and showed positive co-operativity, with a Ki of 62.3 microM and Hill coefficient of 4.0. 6. Plasma and urine levels of SCN- range between 10 and 70 microM, thus the conductance described here may play a role in the regulation of Cl- handling by the kidney.