Separate Swelling- and Ca2+-activated Anion Currents in Ehrlich Ascites Tumor Cells

Separate Swelling- and Ca2+-activated Anion Currents in Ehrlich Ascites Tumor Cells A Ca2+-activated (I Cl,Ca) and a swelling-activated anion current (I Cl,vol) were investigated in Ehrlich ascites tumor cells using the whole cell patch clamp technique. Large, outwardly rectifying currents were activated by an increase in the free intracellular calcium concentration ([Ca2+] i ), or by hypotonic exposure of the cells, respectively. The reversal potential of both currents was dependent on the extracellular Cl− concentration. I Cl,Ca current density increased with increasing [Ca2+] i , and this current was abolished by lowering [Ca2+] i to <1 nm using 1,2-bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetra-acetic acid (BAPTA). In contrast, activation of I Cl,vol did not require an increase in [Ca2+] i . The kinetics of I Cl,Ca and I Cl,vol were different: at depolarized potentials, I Cl,Ca as activated in a [Ca2+] i - and voltage-dependent manner, while at hyperpolarized potentials, the current was deactivated. In contrast, I Cl,vol exhibited time- and voltage-dependent deactivation at depolarized potentials and reactivation at hyperpolarized potentials. The deactivation of I Cl,vol was dependent on the extracellular Mg2+ concentration. The anion permeability sequence for both currents was I − > Cl− > gluconate. I Cl,Ca was inhibited by niflumic acid (100 μm), 5-Nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, 100 μm) and 4,4′-diisothiocyano-2,2′-stilbenedisulfonic acid (DIDS, 100 μm), niflumic acid being the most potent inhibitor. In contrast, I Cl,vol was unaffected by niflumic acid (100 μm), but abolished by tamoxifen (10 μm). Thus, in Ehrlich cells, separate chloride currents, I Cl,Ca and I Cl,vol, are activated by an increase in [Ca2+] i and by cell swelling, respectively. The Journal of Membrane Biology Springer Journals

Separate Swelling- and Ca2+-activated Anion Currents in Ehrlich Ascites Tumor Cells

Loading next page...
Copyright © Inc. by 1998 Springer-Verlag New York
Life Sciences; Biochemistry, general; Human Physiology
Publisher site
See Article on Publisher Site

There are no references for this article.

You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial