Bidirectional Transepithelial Water Transport: Chloride-Dependent Mechanisms

Bidirectional Transepithelial Water Transport: Chloride-Dependent Mechanisms We hypothesized that inhibition and activation of basolateral to luminal chloride transport mechanisms were associated with respective decreases and increases in basolateral to luminal water fluxes. The luminal to basolateral (J W L→B ) and basolateral to luminal (J W B→L ) water fluxes across ovine tracheal epithelia were measured simultaneously. The mean J W L→B (6.5 μl/min/cm2) was larger than J W B→L (6.1 μl/min/cm2). Furosemide reduced J W B→L from 6.0 to 5.6 μl/min/cm2. Diphenylamine-2-carboxylate (DPC) reduced J W B→L from 7.9 to 7.3 μl/min/cm2 and reduced the membrane potential difference by 38%. Furosemide together with DPC decreased J W L→B by 30% and J W B→L by 15%. Norepinephrine increased J W B→L from 4.9 to 6.0 μl/min/cm2. Neuropeptide Y in the presence of norepinephrine decreased J W L→B (6.4 to 5.2 μl/min/cm2) and returned J W B→L to its baseline value. Vasopressin increased J W B→L from 4.1 to 5.1 μl/min/cm2. Endothelin-1 induced a simultaneous increase in J W B→L (7.0 to 7.7 μl/min/cm2) and decrease in J W L→B (7.4 to 6.4 μl/min/cm2); and decreased the membrane resistance. These data indicate that in tracheal epithelia under homeostatic conditions J W B→L has a ∼15% actively coupled component. Consistent with our hypothesis, inhibition and receptor-induced stimulation of chloride effluxes were associated with decreases and increases in J W B→L , respectively. However, as inhibition of transcellular chloride transport always decreased J W L→B more than J W B→L , reducing transepithelial chloride transport did not result in less water being transported into the airway lumen. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Membrane Biology Springer Journals

Bidirectional Transepithelial Water Transport: Chloride-Dependent Mechanisms

Loading next page...
 
/lp/springer_journal/bidirectional-transepithelial-water-transport-chloride-dependent-v7fzdACR2c
Publisher
Springer Journals
Copyright
Copyright © Inc. by 2000 Springer-Verlag New York
Subject
Life Sciences; Biochemistry, general; Human Physiology
ISSN
0022-2631
eISSN
1432-1424
D.O.I.
10.1007/s00232001069
Publisher site
See Article on Publisher Site

Abstract

We hypothesized that inhibition and activation of basolateral to luminal chloride transport mechanisms were associated with respective decreases and increases in basolateral to luminal water fluxes. The luminal to basolateral (J W L→B ) and basolateral to luminal (J W B→L ) water fluxes across ovine tracheal epithelia were measured simultaneously. The mean J W L→B (6.5 μl/min/cm2) was larger than J W B→L (6.1 μl/min/cm2). Furosemide reduced J W B→L from 6.0 to 5.6 μl/min/cm2. Diphenylamine-2-carboxylate (DPC) reduced J W B→L from 7.9 to 7.3 μl/min/cm2 and reduced the membrane potential difference by 38%. Furosemide together with DPC decreased J W L→B by 30% and J W B→L by 15%. Norepinephrine increased J W B→L from 4.9 to 6.0 μl/min/cm2. Neuropeptide Y in the presence of norepinephrine decreased J W L→B (6.4 to 5.2 μl/min/cm2) and returned J W B→L to its baseline value. Vasopressin increased J W B→L from 4.1 to 5.1 μl/min/cm2. Endothelin-1 induced a simultaneous increase in J W B→L (7.0 to 7.7 μl/min/cm2) and decrease in J W L→B (7.4 to 6.4 μl/min/cm2); and decreased the membrane resistance. These data indicate that in tracheal epithelia under homeostatic conditions J W B→L has a ∼15% actively coupled component. Consistent with our hypothesis, inhibition and receptor-induced stimulation of chloride effluxes were associated with decreases and increases in J W B→L , respectively. However, as inhibition of transcellular chloride transport always decreased J W L→B more than J W B→L , reducing transepithelial chloride transport did not result in less water being transported into the airway lumen.

Journal

The Journal of Membrane BiologySpringer Journals

Published: Jun 1, 2000

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 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