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Fluid secretion and the Na+-K+-2Cl- cotransporter in mouse exorbital lacrimal gland.
- Source :
-
American journal of physiology. Cell physiology [Am J Physiol Cell Physiol] 2005 Oct; Vol. 289 (4), pp. C860-7. Date of Electronic Publication: 2005 May 25. - Publication Year :
- 2005
-
Abstract
- We have previously suggested that fluid flow in the mouse exorbital lacrimal gland is driven by the opening of apical Cl- and K+ channels. These ions move into the lumen of the gland and water follows by osmosis. In many tissues, the Na+-K+-2Cl- cotransporter (NKCC1) replaces the Cl- and K+ ions that move into the lumen. We hypothesize that mouse exorbital lacrimal glands would have NKCC1 co-transporters and that they would be important in fluid transport by this gland. We used immunocytochemistry to localize NKCC1-like immunoreactivity to the membranes of the acinar cells as well as to the basolateral membranes of the duct cells. We developed a method to measure tear flow and its composition from mouse glands in situ. Stimulation with the acetylcholine agonist carbachol produced a peak flow followed by a plateau. Ion concentration measurements of this stimulated fluid showed it was high in K+ and Cl-. Treatment of the gland with furosemide, a blocker of the NKCC1 cotransporter, reduced the plateau phase of fluid flow by approximately 30%. Isolated cells exposed to a hypertonic shock shrank by approximately 20% and then showed a regulatory volume increase (RVI). Both the RVI and swelling were blocked by treatment with furosemide. Cells isolated from these glands shrink by approximately 10% in the presence of carbachol. Blocking NKCC1 with furosemide reduced the amount of shrinkage by approximately 50%. These data suggest that NKCC1 plays an important role in fluid secretion by the exorbital gland of mice.
- Subjects :
- Animals
Carbachol pharmacology
Cell Membrane
Cell Size
Diuretics pharmacology
Flufenamic Acid pharmacology
Furosemide pharmacology
Lacrimal Apparatus cytology
Lacrimal Apparatus drug effects
Mice
Mice, Inbred C57BL
Miotics pharmacology
Potassium physiology
Sodium physiology
Sodium-Potassium-Chloride Symporters metabolism
Time Factors
Lacrimal Apparatus metabolism
Sodium-Potassium-Chloride Symporters physiology
Tears metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0363-6143
- Volume :
- 289
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Cell physiology
- Publication Type :
- Academic Journal
- Accession number :
- 15917300
- Full Text :
- https://doi.org/10.1152/ajpcell.00526.2004