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
Published: May 15, 1998
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
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.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera