Functional and Molecular Characterization of a Volume-activated Chloride Channel in Rabbit Corneal Epithelial Cells

Functional and Molecular Characterization of a Volume-activated Chloride Channel in Rabbit... We characterized the functional and molecular properties of a volume-regulated anion channel (VRAC) in SV40-immortalized rabbit corneal epithelial cells (tRCE), since they mediate a robust regulatory volume decrease (RVD) response during exposure to a hypotonic challenge. Whole-cell patch clamp-monitored chloride currents and light- scattering measurements evaluated temporal cell- volume responsiveness to hypoosmotic challenges. Exposure to 200 mOsm medium elicited an outwardly-rectifying current (VACC), which was reversible upon reperfusion with isotonic (300 mOsm) medium. VACC and RVD were chloride-dependent because either chloride removal or application of NPPB (100 μM) suppressed these responses. VACC behavior exhibited voltage-dependent inhibition in the presence of DIDS (500 μM), whereas inhibition by both NPPB (100 μM) and niflumic acid (500 μM) was voltage-independent. VACC was insensitive to glibenclamide (250 μM), verapamil (500 μM) or removal of extracellular calcium. Phorbol dibutyrate, PDBu, (100 nM) had no effect on activated VACC. However, preincubation with PDBu prior to hypotonic challenge prevented VACC and RVD responses as well as prolonged characteristic time. An inactive phorbol ester analogue had no effect on RVD behavior. Moreover, Northern blot analysis verified expression of ClC-3 gene transcripts. The presence of ClC-3 transcripts along with the correspondence between the effects of known ClC-3 inhibitors on VACC and RVD suggest that ClC-3 activation underlies these responses to hypotonic-induced cell swelling. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Membrane Biology Springer Journals

Functional and Molecular Characterization of a Volume-activated Chloride Channel in Rabbit Corneal Epithelial Cells

Loading next page...
 
/lp/springer_journal/functional-and-molecular-characterization-of-a-volume-activated-UEJjv5LGcJ
Publisher
Springer-Verlag
Copyright
Copyright © 2004 by Springer Science+Business Media, Inc.
Subject
Life Sciences; Human Physiology; Biochemistry, general
ISSN
0022-2631
eISSN
1432-1424
D.O.I.
10.1007/s00232-004-0706-5
Publisher site
See Article on Publisher Site

Abstract

We characterized the functional and molecular properties of a volume-regulated anion channel (VRAC) in SV40-immortalized rabbit corneal epithelial cells (tRCE), since they mediate a robust regulatory volume decrease (RVD) response during exposure to a hypotonic challenge. Whole-cell patch clamp-monitored chloride currents and light- scattering measurements evaluated temporal cell- volume responsiveness to hypoosmotic challenges. Exposure to 200 mOsm medium elicited an outwardly-rectifying current (VACC), which was reversible upon reperfusion with isotonic (300 mOsm) medium. VACC and RVD were chloride-dependent because either chloride removal or application of NPPB (100 μM) suppressed these responses. VACC behavior exhibited voltage-dependent inhibition in the presence of DIDS (500 μM), whereas inhibition by both NPPB (100 μM) and niflumic acid (500 μM) was voltage-independent. VACC was insensitive to glibenclamide (250 μM), verapamil (500 μM) or removal of extracellular calcium. Phorbol dibutyrate, PDBu, (100 nM) had no effect on activated VACC. However, preincubation with PDBu prior to hypotonic challenge prevented VACC and RVD responses as well as prolonged characteristic time. An inactive phorbol ester analogue had no effect on RVD behavior. Moreover, Northern blot analysis verified expression of ClC-3 gene transcripts. The presence of ClC-3 transcripts along with the correspondence between the effects of known ClC-3 inhibitors on VACC and RVD suggest that ClC-3 activation underlies these responses to hypotonic-induced cell swelling.

Journal

The Journal of Membrane BiologySpringer Journals

Published: Jan 1, 2004

References

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 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

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

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off