scholarly journals Origin of positive transepithelial potential difference in early distal segments of rat kidney

1985 ◽  
Vol 27 (4) ◽  
pp. 622-629 ◽  
Author(s):  
Glen G. Allen ◽  
Lindsay J. Barratt
Keyword(s):  
Rat Kidney ◽  
Potential Difference ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

scholarly journals Transepithelial potential difference profile of the distal tubule of the rat kidney

1975 ◽  
Vol 8 (6) ◽  
pp. 368-375 ◽  
Author(s):  
Lindsay J. Barratt ◽  
Floyd C. Rector ◽  
Juha P. Kokko ◽  
C. Craig Tisher ◽  
Donald W. Seldin
Keyword(s):  
Rat Kidney ◽  
Distal Tubule ◽  
Potential Difference ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

Nitric oxide-mediated regulation of transepithelial sodium and chloride transport in murine nasal epithelium

1999 ◽  
Vol 276 (3) ◽  
pp. L466-L473 ◽  
Author(s):  
Heather L. Elmer ◽  
Kristine G. Brady ◽  
Mitchell L. Drumm ◽  
Thomas J. Kelley
Keyword(s):  
Nitric Oxide ◽  
Chloride Transport ◽  
Chloride Secretion ◽  
Inos Expression ◽  
Potential Difference ◽  
Nasal Epithelium ◽  
Sodium Absorption ◽  
No Production ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

Transepithelial ion transport is regulated by a variety of cellular factors. In light of recent evidence that nitric oxide (NO) production is decreased in cystic fibrosis airways, we examined the role of NO in regulating sodium and chloride transport in murine nasal epithelium. Acute intervention with the inducible NO synthase (iNOS)-selective inhibitor S-methylisothiourea resulted in an increase of amiloride-sensitive sodium absorption observed as a hyperpolarization of nasal transepithelial potential difference. Inhibition of iNOS expression with dexamethasone also hyperpolarized transepithelial potential difference, but only a portion of this increase proved to be amiloride sensitive. Chloride secretion was significantly inhibited in C57BL/6J mice by the addition of both S-methylisothiourea and dexamethasone. Mice lacking iNOS expression [NOS2(−/−)] also had a decreased chloride-secretory response compared with control mice. These data suggest that constitutive NO production likely plays some role in the downregulation of sodium absorption and leads to an increase in transepithelial chloride secretion.

Calcium secretion in canine tracheal mucosa

1985 ◽  
Vol 59 (4) ◽  
pp. 1191-1195 ◽  
Author(s):  
F. J. Al-Bazzaz ◽  
T. Jayaram
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Potential Difference ◽  
Secretory Process ◽  
Metabolic Inhibitor ◽  
Tracheal Mucosa ◽  
Transepithelial Potential ◽  
Transepithelial Potential Difference

Calcium (Ca) affects many cellular functions of the respiratory tract mucosa and might alter the viscoelastic properties of mucus. To evaluate Ca homeostasis in a respiratory epithelium we investigated transport of Ca by the canine tracheal mucosa. Mucosal tissues were mounted in Ussing-type chambers and bathed with Krebs-Henseleit solution at 37 degrees C. Unidirectional fluxes of 45Ca were determined in tissues that were matched by conductance and short-circuit current (SCC). Under short-circuit conditions there was a significant net Ca secretion of 1.82 +/- 0.36 neq . cm-2 . h-1 (mean +/- SE). Under open-circuit conditions, where the spontaneous transepithelial potential difference could attract Ca toward the lumen, net Ca secretion increased significantly to 4.40 +/- 1.14 compared with 1.54 +/- 1.17 neq . cm-2 . h-1 when the preparation was short-circuited. Addition of a metabolic inhibitor, 2,4-dinitrophenol (2 mM in the mucosal bath), decreased tissue conductance and SCC and slightly decreased the unidirectional movement of Ca from submucosa to lumen. Submucosal epinephrine (10 microM) significantly enhanced Ca secretion by 2.0 +/- 0.63 neq . cm-2 . h-1. Submucosal ouabain (0.1 mM) failed to inhibit Ca secretion. The data suggest that canine tracheal mucosa secretes Ca; this secretory process is augmented by epinephrine or by the presence of a transepithelial potential difference as found under in vivo conditions.

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