Studies on H+-ATPase in Cultured Rabbit Nonpigmented Ciliary Epithelium

Studies on H+-ATPase in Cultured Rabbit Nonpigmented Ciliary Epithelium Studies were conducted to examine the influence of the H+-ATPase inhibitor bafilomycin A1 on cultured rabbit nonpigmented ciliary epithelial cells (NPE). Cytoplasmic pH and sodium concentrations were measured by digital fluorescence microscopy using BCECF and SBFI respectively. In some experiments, cell sodium content was measured by atomic absorption spectroscopy. Added alone, bafilomycin A1 (100 nm) failed to change cytoplasmic pH but it caused an increase of cytoplasmic sodium concentration which occurred within 10 min. It is likely that the rise of cytoplasmic sodium concentration was responsible for the stimulation of active sodium-potassium transport which occurred in bafilomycin A1-treated cells as judged by a 50% increase of ouabain sensitive potassium (86Rb) uptake. In bafilomycin A1-treated cells, but not in control cells, dimethylamiloride (DMA) inhibited ouabain-sensitive potassium (86Rb) uptake in a dose-dependent manner with an IC50 of ∼2 μm. DMA (10 μm) also prevented the increase of cytoplasmic sodium caused by bafilomycin A1. Added alone, DMA (10 μm) failed to change cytoplasmic sodium content but reduced cytoplasmic pH by ∼0.4 pH units. In cells that first received 10 μm DMA, the subsequent addition of bafilomycin A1 (100 nm) caused a further cytoplasmic pH reduction of ∼0.3 pH units. Taken together, the results suggest H+-ATPase might contribute to the regulation of basal cytoplasmic pH in cultured NPE. In the presence of bafilomycin A1, Na-H exchanger activity appears to be stimulated, so stabilizing cytoplasmic pH but resulting in an increase of cytoplasmic sodium concentration and consequent stimulation of active sodium-potassium transport. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Membrane Biology Springer Journals

Studies on H+-ATPase in Cultured Rabbit Nonpigmented Ciliary Epithelium

Loading next page...
 
/lp/springer_journal/studies-on-h-atpase-in-cultured-rabbit-nonpigmented-ciliary-epithelium-5GWNZZIO6t
Publisher
Springer-Verlag
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/s002320001008
Publisher site
See Article on Publisher Site

Abstract

Studies were conducted to examine the influence of the H+-ATPase inhibitor bafilomycin A1 on cultured rabbit nonpigmented ciliary epithelial cells (NPE). Cytoplasmic pH and sodium concentrations were measured by digital fluorescence microscopy using BCECF and SBFI respectively. In some experiments, cell sodium content was measured by atomic absorption spectroscopy. Added alone, bafilomycin A1 (100 nm) failed to change cytoplasmic pH but it caused an increase of cytoplasmic sodium concentration which occurred within 10 min. It is likely that the rise of cytoplasmic sodium concentration was responsible for the stimulation of active sodium-potassium transport which occurred in bafilomycin A1-treated cells as judged by a 50% increase of ouabain sensitive potassium (86Rb) uptake. In bafilomycin A1-treated cells, but not in control cells, dimethylamiloride (DMA) inhibited ouabain-sensitive potassium (86Rb) uptake in a dose-dependent manner with an IC50 of ∼2 μm. DMA (10 μm) also prevented the increase of cytoplasmic sodium caused by bafilomycin A1. Added alone, DMA (10 μm) failed to change cytoplasmic sodium content but reduced cytoplasmic pH by ∼0.4 pH units. In cells that first received 10 μm DMA, the subsequent addition of bafilomycin A1 (100 nm) caused a further cytoplasmic pH reduction of ∼0.3 pH units. Taken together, the results suggest H+-ATPase might contribute to the regulation of basal cytoplasmic pH in cultured NPE. In the presence of bafilomycin A1, Na-H exchanger activity appears to be stimulated, so stabilizing cytoplasmic pH but resulting in an increase of cytoplasmic sodium concentration and consequent stimulation of active sodium-potassium transport.

Journal

The Journal of Membrane BiologySpringer Journals

Published: Jan 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