Effects of Aerosolized Amiloride on Mucociliary Transport Velocity and Transepithelial Potential Difference in Isolated Frog Palate

1995 ◽  
Vol 8 (2) ◽  
pp. 167-176 ◽  
Author(s):  
ELIANE FESTA ◽  
MARIANGELA MACCHIONE ◽  
PAULO S.O. PAIVA ◽  
PAULO H.N. SALDIVA ◽  
MALCOLM KING
2005 ◽  
Vol 19 (4) ◽  
pp. 353-357 ◽  
Author(s):  
Mônica Aidar Menon-Miyake ◽  
Regiani Carvalho de Oliveira ◽  
Geraldo Lorenzi-Filho ◽  
Paulo Hilário Nascimento Saldiva ◽  
Ossamu Butugan

Background Luffa operculata is a medicinal plant used in homeopathic and alternative medicine. In the United States, it is sold in a purified spray form, whereas a homemade L. operculata dry fruit infusion (DFI) is commonly used in Latin America. The L. operculata DFI is applied intranasally, inducing profuse mucous secretion and relieving nasal symptoms. Nevertheless, this medication may cause irritation of the nasal mucosa, as well as epistaxis or anosmia. Given the growing popularity of alternative medicine, a decision was made to evaluate the effects of this substance on mucous membranes. Methods The effects of L. operculata DFI on mucociliary transport velocity, ciliary beat frequency, and transepithelial potential difference (PD) were evaluated in an isolated frog palate preparation. We tested 46 palates immediately before immersion and again at 5 and 20 minutes after immersion. Four groups (n = 10) were tested in frog Ringer: control; L. operculata DFI, 60 mg/L; 600 mg/L; and 1200 mg/L. An additional group was tested using L. operculata DFI prepared with water (600 mg/L of H2O, n = 6). Epithelial samples were harvested for ultrastructural study. Results In treated palates, mucociliary transport velocity and ciliary beat frequency decreased significantly (p < 0.001 and p < 0.008, respectively). There was a dose-dependent decrease in PD modulus (p < .007). Our PD findings indicated ion-fluid transport abnormalities, which were confirmed by transmission electron microscopy that showed enlargement of interepithelial spaces. Conclusion In this ex vivo model, the L. operculata DFI infusion promoted significant changes in the mucociliary function of the epithelium, suggesting that it is potentially noxious to human nasal mucosa.


1999 ◽  
Vol 276 (3) ◽  
pp. L466-L473 ◽  
Author(s):  
Heather L. Elmer ◽  
Kristine G. Brady ◽  
Mitchell L. Drumm ◽  
Thomas J. Kelley

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.


1985 ◽  
Vol 59 (4) ◽  
pp. 1191-1195 ◽  
Author(s):  
F. J. Al-Bazzaz ◽  
T. Jayaram

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.


2010 ◽  
Vol 9 ◽  
pp. S20 ◽  
Author(s):  
S.M. Rowe ◽  
J.P. Clancy ◽  
M. Boyle ◽  
F. Van Goor ◽  
C. Ordonez ◽  
...  

1978 ◽  
Vol 234 (3) ◽  
pp. F182-F191 ◽  
Author(s):  
J. P. Hayslett ◽  
E. L. Boulpaep ◽  
G. H. Giebisch

Studies were performed to examine some electrical properties of the mammalian distal tubule. Experiments were performed to evaluate the influence of changes in ion concentration in luminal fluid on transepithelial potential difference. Variations in the concentration of Na+ and K+, near the physiologic range, resulted in only modest changes in potential difference. During changes in Na+ the average slope, deltaV/ln C2/C1, was -1.52 +/- 0.39 mV and during variations in K+ the slope was -5.60 +/- 0.95 mV. Changes in Cl- concentration had no effect on transepithelial potential difference. Since the sum of transferase numbers did not equal 1, it seems likely that potential difference is influenced by a shunt current due to cellular rheogenic pumps. These data, therefore, indicate that variations in ion concentration in tubular fluid of the mammalian distal tubule do not significantly influence the resting transepithelial potential difference, and they suggest that analysis of permselective properties of the luminal cell membrane by transepithelial electrophysiologic approaches is probably invalid.


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