The sodium concentration of the lateral intercellular spaces of MDCK cells: a microspectrofluorimetric study
Details
Serval ID
serval:BIB_74D26F1188FB
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The sodium concentration of the lateral intercellular spaces of MDCK cells: a microspectrofluorimetric study
Journal
Journal of Membrane Biology
ISSN
0022-2631 (Print)
Publication state
Published
Issued date
03/1995
Volume
144
Number
1
Pages
11-9
Notes
Journal Article --- Old month value: Mar
Abstract
MDCK cell monolayers grown on glass coverslips were used to examine the Na+ concentration in individual lateral intercellular spaces (LIS) by video fluorescence microscopy. The LIS was filled with the Na(+)-sensitive fluorescent dye SBFO by incubation of the monolayers for 75-90 min with 250 microM of the membrane impermeant form of the dye. After dye loading, the monolayers were perfused at 37 degrees C with solutions buffered with HEPES or bicarbonate/CO2 containing 142 mM Na+. Ratios of the fluorescence images after sequential excitation with 340 nm and 380 nm light were performed and in situ calibration of LIS Na+ was accomplished after blocking the Na+ pump with 5 x 10(-4) M ouabain. Measurements of Na+ along the basolateral-to-apical axis of the LIS at 1.0 or 1.5 microns intervals did not reveal a Na+ gradient when the perfusate was either HEPES or bicarbonate/CO2 solutions. In bicarbonate solutions, the mean Na+ concentration (mM) was 157.2 +/- 2.3, approximately 15 mM higher than the bath Na+ concentration. In HEPES solutions, however, the Na+ concentration was not different from the bath concentration (142.7 +/- 3.1 mM). The time course of Na+ changes in LIS was investigated by rapidly switching the perfusate from 142 to 80 mM Na+ and measuring the Na+ changes at one focal plane.
Keywords
Animals
Cell Line
Dogs
Extracellular Space/chemistry
Fluorescent Dyes
Kidney/*chemistry/cytology
Microchemistry
Microscopy, Fluorescence/*methods
Na(+)-K(+)-Exchanging ATPase/antagonists & inhibitors
Ouabain/pharmacology
Sodium/*analysis
Spectrometry, Fluorescence/*methods
Video Recording
Pubmed
Web of science
Create date
24/01/2008 14:08
Last modification date
20/08/2019 15:32