Restitution of the bullfrog gastric mucosa is dependent on a DIDS-inhibitable pathway not related to \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{HCO}_{3}^{-}\) \end{document} ion transport

2004 ◽  
Vol 286 (4) ◽  
pp. G596-G605 ◽  
Author(s):  
Susan J. Hagen ◽  
Sarah W. Morrison ◽  
Christina S. Law ◽  
David X. Yang
Keyword(s):  
Cell Migration ◽  
Gastric Mucosa ◽  
Basement Membrane ◽  
Ion Transport ◽  
Rana Catesbeiana ◽  
Transepithelial Resistance ◽  
Ussing Chambers ◽  
Ion Substitution ◽  
Transport Inhibitors ◽  
Mannitol Flux

This study was conducted to determine the contribution of ion transport to restitution after injury in the gastric mucosa. For this, intact sheets of stomach from the bullfrog, Rana catesbeiana, were mounted in Ussing chambers. Restitution was evaluated in the presence or absence of ion transport inhibitors amiloride, DIDS, and bumetanide to block Na+/H+ exchange, [Formula: see text]/[Formula: see text] exchange and [Formula: see text]/[Formula: see text] co-transport, and Na+-K+-2Cl- cotransport, respectively. Ion substitution experiments with Na+-free, Cl--free, and [Formula: see text]-free solutions were also performed. Injury to the mucosa was produced with 1 M NaCl, and restitution was evaluated by recovery of transepithelial resistance (TER), mannitol flux, and morphology. Amiloride, bumetanide, Cl--free, or [Formula: see text]-free solutions did not affect restitution. In Na+-free solutions, recovery of TER and mannitol flux did not occur because surface cells did not attach to the underlying basement membrane. In contrast, all aspects of restitution were inhibited by DIDS, a compound that inhibits Na+-dependent [Formula: see text] transport. Because [Formula: see text]-free solutions did not inhibit restitution, it was concluded that DIDS must block a yet undefined pathway not involved in [Formula: see text] ion transport but essential for cell migration after injury and restitution in the gastric mucosa.

Purinergic regulation of ion transport across nonciliated bronchiolar epithelial (Clara) cells

1995 ◽  
Vol 269 (1) ◽  
pp. L30-L37 ◽  
Author(s):  
M. R. Van Scott ◽  
T. C. Chinet ◽  
A. D. Burnette ◽  
A. M. Paradiso
Keyword(s):  
Ion Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Initial Response ◽  
Extracellular Nucleotides ◽  
Clara Cells ◽  
Pyrimidine Nucleotides ◽  
Ion Substitution ◽  
Transport Inhibitors ◽  
Effective Doses

Previous studies demonstrated that elevation of intracellular calcium concentration ([Ca2+]i) increased electrogenic anion transport by bronchiolar epithelia. Extracellular nucleotides were shown to elevate [Ca2+]i and transepithelial short-circuit current (Isc) in proximal airways epithelia. In this study purine and pyrimidine nucleotides were investigated for their ability to regulate ion transport by rabbit nonciliated bronchiolar epithelial (Clara) cells in culture. ATP in the apical bath induced a concentration-dependent transient increase in [Ca2+]i and Isc. Mean effective doses (ED50) of the responses were 10(-7) M and 10(-6) M, respectively. Transepithelial resistance (Rt) decreased. The peak changes in Isc and Rt were 7.8 +/- 1.2 microA/cm2 and -59 +/- 14 omega.cm2 (n = 26, basal Isc = 47.4 +/- 4.3 microA/cm2 and Rt = 428 +/- 40 omega.cm2). Some preparations exhibited a small residual increase in Isc after the initial response, but the change was not statistically significant (delta Isc = 1.7 +/- 1.2 microA/cm2, n = 18). Addition of ATP to the basolateral bath had no detectable effects. Purinoceptor agonists were used to characterize the receptors mediating the change in Isc. UTP and ATP gamma S increased Isc and inhibited subsequent stimulation by ATP. ADP, ADP beta S, 2-methylthio-ATP, and alpha, beta-methylene-ATP had negligible effects on the peak delta Isc and subsequent stimulation by ATP. The ionic mechanism underlying the ATP-induced increase in Isc was investigated with the use of specific ion-transport inhibitors and by ion substitution.(ABSTRACT TRUNCATED AT 250 WORDS)

Anomalies in ion transport in CF mouse tracheal epithelium

1994 ◽  
Vol 267 (1) ◽  
pp. C293-C300 ◽  
Author(s):  
B. R. Grubb ◽  
A. M. Paradiso ◽  
R. C. Boucher
Keyword(s):  
Gene Transfer ◽  
Ion Transport ◽  
Short Circuit ◽  
Tracheal Epithelium ◽  
Na Transport ◽  
Pharmacological Agents ◽  
Ussing Chambers ◽  
Relative Contribution ◽  
Ion Substitution ◽  
Cl Conductance

The cystic fibrosis (CF) mouse trachea has become a model for gene transfer. To characterize ion transport properties of tracheal epithelium from normal and CF mice, tracheas were excised, mounted in Ussing chambers, and basal properties and responses to pharmacological agents and/or ion substitution protocols measured. No difference in basal short-circuit (Isc) was observed between normal (29.1 +/- 3.8 muA/cm2, n = 21) and CF (34.7 +/- 4.5 muA/cm2, n = 16) tracheas. The relative contribution of Na+ transport to basal Isc was small (30-40%). Ionomycin stimulated large increases in Isc in both normal and CF murine tracheas [change in Isc (delta Isc) with ionomycin: 30.5 +/- 8.8 muA/cm2, n = 11, normal; 27.3 +/- 6.7 muA/cm2, n = 6, CF]. Unexpectedly, forskolin increased Isc in both CF and normal amiloride-pretreated tracheas (delta Isc: 10.5 +/- 2.1 muA/cm2, n = 21, normal; 13 +/- 2.3 muA/cm2, n = 16, CF). Forskolin was observed to increase intracellular Ca2+ in both normal and CF tracheal cells, suggesting this as a mechanism to induce Cl- secretion. These similarities in ion transport, in part reflecting the dominance of Ca(2+)-regulated Cl- conductance, suggest that the murine trachea is not an ideal target for assessment of CF correction by gene transfer.

Regulation of acid secretion and paracellular permeability by F-actin in the bullfrog,Rana catesbeiana

2002 ◽  
Vol 282 (3) ◽  
pp. G519-G526 ◽  
Author(s):  
Tarik A. Abdul-Ghaffar Al-Shaibani ◽  
Susan J. Hagen
Keyword(s):  
Acid Secretion ◽  
Actin Filaments ◽  
Rana Catesbeiana ◽  
Paracellular Permeability ◽  
Bicarbonate Transport ◽  
Back Diffusion ◽  
Mucosal Permeability ◽  
Ussing Chambers ◽  
Junction Structure ◽  
Mannitol Flux

G526, 2002. First published December 5, 2001; 10.1152/ajpgi.00393. 2001.—Many studies have implicated F-actin in the regulation of gastric acid secretion using cytochalasin D (CD) to disrupt apical actin filaments in oxyntic cells. However, it is known that CD also affects mucosal permeability by disrupting tight junction structure. Here we investigated the contribution of F-actin to mucosal permeability and acid secretion in the stomach using CD. Stomachs were mounted in Ussing chambers and acid secretion (stimulated or inhibited), transepithelial resistance (TER), mannitol flux, bicarbonate transport, and dual mannitol/sodium fluxes were determined with or without CD. H+back diffusion was predicted from its diffusion coefficient. Incubation with CD resulted in a significant reduction in stimulated acid secretion. TER was unchanged in stimulated tissues but significantly reduced in inhibited tissues. Mannitol flux, bicarbonate transport, and H+-back diffusion increased significantly with CD. However, the rates of bicarbonate and H+flux were not large enough to account for the inhibition of acid secretion. These findings demonstrate that actin filaments regulate paracellular permeability and play an essential role in the regulation of acid secretion in the stomach.

The application of Ussing chambers for determining the impact of microbes and probiotics on intestinal ion transport

2013 ◽  
Vol 91 (9) ◽  
pp. 663-670 ◽  
Author(s):  
Kevin W. Lomasney ◽  
Niall P. Hyland
Keyword(s):  
Ion Transport ◽  
Animal Studies ◽  
Ussing Chamber ◽  
Positive Influence ◽  
Mechanisms Of Action ◽  
Ussing Chambers ◽  
Host Microbe Interactions ◽  
The Impact ◽  
Intestinal Ion Transport

Host–microbe interactions have gained considerable attention in recent years with regards to their role in various organic disorders and diseases. In particular, research efforts have focused on the intestinal microbiota, where the largest and most diverse populations not only co-exist with the host, but also directly influence the state and function of the gastrointestinal (GI) tract. Moreover, both human and animal studies alike are now beginning to show a positive influence of probiotic bacteria on GI disorders associated with diarrhoea or constipation. Diarrheagenic GI diseases, such as those caused by Vibreo cholera or enterpathogenic Eschericia coli, have well-characterised interactions with the host that explain much of the observed symptoms, in particular severe diarrhoea. However, the mechanisms of action of nonpathogenic bacteria or probiotics on host physiology are less clearly understood. In the context of defining the mechanisms of action of probiotics in vitro, the Ussing chamber has proven to be a particularly useful tool. Here, we will present data from several studies that have defined molecular targets for microbes and putative probiotics in the regulation of intestinal secretory and absorptive function, and we will discuss these in the context of their application in pathogen- or inflammation-induced alterations in intestinal ion transport.

scholarly journals MIG-17/ADAMTS controls cell migration by recruiting nidogen to the basement membrane in C. elegans

2008 ◽  
Vol 105 (52) ◽  
pp. 20804-20809 ◽  
Author(s):  
Y. Kubota ◽  
K. Ohkura ◽  
K. K. Tamai ◽  
K. Nagata ◽  
K. Nishiwaki
Keyword(s):  
Cell Migration ◽  
Basement Membrane ◽  
C Elegans

scholarly journals Purification of Gastric Mucosal ECL Cells from a Crude Elutriation Fraction

2002 ◽  
Vol 2 ◽  
pp. 1643-1645 ◽  
Author(s):  
John Graham
Keyword(s):  
Gastric Mucosa ◽  
Ion Transport ◽  
Parietal Cell ◽  
Cell Function ◽  
Parietal Cells ◽  
Centrifugal Elutriation ◽  
Ecl Cells ◽  
Acid Secreting ◽  
Density Barrier

Acid-secreting parietal cells from the gastric mucosa are widely studied as a model in studies on ion transport and the endocrine/paracrine ECL cells effectively control parietal cell function. Discontinuous gradients of iodixanol for the purification of ECL cells were subsequently simplified to the use of a density barrier. This technique is now commonly used following initial centrifugal elutriation.

Vasoactive intestinal peptide stimulates protein phosphorylation in a colonic epithelial cell line

1987 ◽  
Vol 253 (3) ◽  
pp. G420-G424 ◽  
Author(s):  
J. A. Cohn
Keyword(s):  
Epithelial Cell ◽  
Ion Transport ◽  
Protein Phosphorylation ◽  
Cell Line ◽  
Vasoactive Intestinal Peptide ◽  
Epithelial Cell Line ◽  
Colonic Epithelial Cell ◽  
Ussing Chambers ◽  
Colonic Epithelial Cell Line ◽  
Stimulation Of

The T84 colonic epithelial cell line was used to examine protein phosphorylation during neurohumoral stimulation of ion transport. T84 cell monolayers grown on collagen-coated filters were mounted in Ussing chambers to measure ion transport stimulated by vasoactive intestinal peptide. Maximal stimulation of active secretion occurred after 8-10 min of stimulation. Protein phosphorylation events accompanying stimulated secretion were detected using two-dimensional gel electrophoresis to resolve phosphoproteins from monolayers previously labeled using 32Pi. Within 8 min of exposure to vasoactive intestinal peptide, several phosphorylation events were detected, including a two- to fivefold increase in 32P incorporation into four soluble proteins with apparent molecular weights of 17,000, 18,000, 23,000, and 37,000. The same phosphorylation response occurs in monolayers stimulated by dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP), suggesting that cAMP mediates these intracellular events. This study indicates that changes in protein phosphorylation accompany the secretory action of vasoactive intestinal peptide and suggests that T84 cells offer a useful model for studying the possibility that such phosphorylation events regulate enterocyte ion transport.

Effects of ammonium ion and ammonia on function and morphology of in vitro frog gastric mucosa

1993 ◽  
Vol 265 (2) ◽  
pp. G277-G288 ◽  
Author(s):  
A. Yanaka ◽  
H. Muto ◽  
S. Ito ◽  
W. Silen
Keyword(s):  
Gastric Mucosa ◽  
Electrical Resistance ◽  
Rana Catesbeiana ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Ammonium Ion ◽  
Gastric Epithelial Cells ◽  
Sudden Drop ◽  
Oxynticopeptic Cells

The effects of ammonium ion (NH+4) and ammonia (NH3) on function and morphology of gastric epithelial cells were studied in intact sheets of in vitro frog (Rana catesbeiana) gastric mucosa. Luminal 115 mM NH4Cl at luminal pH 8.0 (calculated [NH3] 2.7 mM), but not at 5.0 (calculated [NH3] 3 microM) induced 1) an increase in intracellular pH (pHi) in oxynticopeptic cells (OPC) and decreases in transmucosal potential difference (PD) and electrical resistance (R) in resting tissues, 2) a decrease in histamine-stimulated H+ secretion and an increase in H+ backdiffusion after removal of luminal NH4Cl, and 3) augmented acidification of OPC during luminal acidification. Serosal 30 mM NH4Cl at serosal pH 7.2 (calculated [NH3] 0.47 mM) induced 1) an increase in pHi in OPC and inhibition of the alkalinization of OPC after removal of ambient Cl-, 2) a decrease in PD associated with the increase in R and decrease in short-circuit current, effects attenuated by serosal 15 mM K+, accentuated by 0.2 mM Ba2+, and abolished by removal of ambient Cl-, 3) a sudden drop of PD in resting, but not in stimulated tissues, effects prevented by high serosal pH (7.8), serosal HCO3-, or removal of luminal Cl-, 4) a decrease in histamine-stimulated H+ secretion and an increase in H+ backdiffusion after removal of NH4Cl, and 5) augmented acidification of OPC during luminal acidification. These results suggest that 1) luminal NH3, but not NH+4, increases backdiffusion of H+ from the lumen to the mucosa, 2) serosal NH3 and/or NH+4 induces depolarization of OPC and decreases electrogenic Cl- transport, thereby attenuating the activity of the basolateral Cl(-)-HCO3- exchanger in OPC, and 3) both of these effects contribute to the augmented acidification of OPC during exposure to high luminal [H+].

Secretion of H+ and K+ by bullfrog gastric mucosa: characterization of K+ transport pathway

1980 ◽  
Vol 239 (6) ◽  
pp. G485-G492
Author(s):  
P. C. Sen ◽  
L. L. Tague ◽  
T. K. Ray
Keyword(s):  
Gastric Mucosa ◽  
Nutrient Solution ◽  
Rana Catesbeiana ◽  
Transport Pathway ◽  
Mucosal Side ◽  
Apical Membranes ◽  
K Transport ◽  
Co2 Addition

The transport of K+ and H+ (both expressed as mueq/h) by in vitro chambered bullfrog (Rana catesbeiana) gastric mucosa have been studied under a variety of conditions such as anoxia, addition of p-chloromercuribenzene sulfonic acid (PCMBS) into the secretory solution, inclusion of ouabain in the nutrient solution, addition of thiocyanate (SCN-) into the mucosal solution, and replacement of nutrient chloride (Cl-) with sulfate (SO4(2-)), or gluconate (Gl). Anoxia reversibly reduced the H+ transport close to zero within 15 min and gradually reduces the K+ transport throughout the 2-h period of anoxia. The presence of 2.5 X 10(-4) M mucosal PCMBS in the histamine-stimulated mucosa increases the K+ transport, which is promptly reduced by changing the gas phase to 95% N2-5% CO2. Addition of ouabain to the nutrient solution of the histamine-stimulated mucosa with PCMBS on the mucosal side significantly (P < 0.05) reduces the K+ transport within 60 min. Addition of SCN- to the mucosal solution of a histamine-stimulated mucosa with regular nutrient or O, K+ nutrient and 10, K+ mucosal solution reduces the H+ transport to near zero within 60 min. This SCN- inhibition can be reversed by elevating secretory K+. Substitution of nutrient Cl- with SO4(2-) or Gl in the histamine-stimulated mucosa reversibly inhibits H+ transport and reduces K+ transport to a low level (0.7 +/- 0.05). Our data suggest that the K+ transport across the apical membranes of gastric cells is to a large extent a passive carrier-mediated process, and the transport of both K+ and Cl- are coupled at the apical membrane.

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