Effect of histamine on the basolateral K+ conductance of frog stomach oxyntic cells and surface epithelial cells

1990 ◽  
Vol 258 (4) ◽  
pp. G631-G636
Author(s):  
L. Debellis ◽  
S. Curci ◽  
E. Fromter
Keyword(s):  
Epithelial Cells ◽  
Basolateral Membrane ◽  
Voltage Divider ◽  
Cell Types ◽  
Membrane Resistance ◽  
Rana Esculenta ◽  
Frog Stomach ◽  
K Concentration ◽  
Voltage Divider Ratio ◽  
Ion Conductances

The transepithelial potential difference (Vt) and resistance (Rt) and the basolateral cell membrane potential (Vs) of oxyntic cells (OC) and surface epithelial cells (SEC) were measured in isolated stomachs of Rana esculenta. At rest, Vs of OC and SEC was virtually identical [-66.3 +/- 4.5 (SD) (n = 10) and -67.3 +/- 5.9 mV (n = 9)] and both cells responded to increasing serosal K+ concentration from 4 to 13 mmol/l with virtually the same depolarization (delta Vs,K) of +16.2 +/- 2.0 and +16.0 +/- 2.9 mV, respectively, while Vt declined by approximately half as much. Histamine (0.1 mmol/l) reduced Vt and Rt and increased the voltage divider ratio in both cell types, indicating a fall in basolateral membrane resistance. In the OC, this increase was neither associated with a significant alteration of Vs nor with a change in delta Vs,K. In the SEC, however, histamine markedly increased Vs to -75.5 +/- 7.3 mV (n = 9) as well as delta Vs,K to +18.5 +/- 2.6 mV, which was paralleled by an increase in delta Vt,K from 9.8 +/- 3.9 to +12.8 +/- 4.2 mV. The data indicate that 1) both OC and SEC respond to histamine, 2) both OC and SEC contain a basolateral K+ conductance that increases under histamine (in OC probably, in parallel with other ion conductances), and 3) in Rana esculenta the SEC contribute substantially to Vt.

Electrophysiological characterization of upper portion of descending limb of long-looped nephron

1991 ◽  
Vol 260 (3) ◽  
pp. F311-F316 ◽  
Author(s):  
K. Yoshitomi ◽  
M. Imai
Keyword(s):  
Apical Membrane ◽  
Basolateral Membrane ◽  
High Water ◽  
Membrane Resistance ◽  
Membrane Voltage ◽  
Major Pathway ◽  
K Concentration ◽  
Electrophysiological Characterization

The upper portion of the descending limb of long-looped nephron (LDLu) of the hamster is characterized by high water and ion permeabilities. Although the paracellular route is considered to be the major pathway representing cation permselectivity of this segment, ion transport mechanisms through the transcellular pathway are unknown. To study this issue; we applied cable analysis and conventional microelectrode technique to the hamster LDLu perfused in vitro. The transmural voltage (VT) was not different from zero, and transmural resistance (RT) was very low, 18.3 +/- 2.0 omega.cm2 (n = 12). The basolateral membrane voltage was -80 +/- 2 mV (n = 55), and fractional apical membrane resistance was 0.92 +/- 0.23 (n = 5). Ouabain (0.1 mM) in the bath decreased basolateral membrane voltage (VB) by 23 +/- 3 mV (n = 6, P less than 0.001). Increase in K+ concentration in bath and in lumen from 5 to 50 mM decreased VB by 39 +/- 2 (n = 7, P less than 0.01) and apical membrane voltage (VA) by 10 +/- 1 mV (n = 7, P less than 0.001), respectively. Addition of 2 mM Ba2+ to bath and to lumen decreased VB by -47 +/- 2 (n = 11, P less than 0.001) and decreased VA by 8 +/- 1 mV, respectively. Reduction of HCO3- in bath from 25 to 2.5 mM decreased VB by 4 +/- 1 mV (n = 7, P less than 0.005). Reduction of bath Cl- did not cause any rapid deflection of VB. No appreciable Na+ conductance was detected in the apical membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Contribution of surface epithelial cells to total conductance of Necturus gastric fundus mucosa

1996 ◽  
Vol 270 (6) ◽  
pp. G902-G908 ◽  
Author(s):  
G. Kottra ◽  
C. Iacovelli ◽  
R. Caroppo ◽  
S. Curci ◽  
P. Bakos ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Voltage Divider ◽  
Gastric Fundus ◽  
Total Conductance ◽  
In Vitro Activation ◽  
Transepithelial Voltage ◽  
Gastric Fundus Mucosa ◽  
Voltage Divider Ratio ◽  
Microelectrode Techniques

Microelectrode techniques were used to quantify the contribution of surface epithelial cells (SEC) to transepithelial conductance (gt) of Necturus gastric fundus mucosa. Transepithelial voltage (Vt) and resistance (Rt) as well as the basolateral cell membrane potential (Vb) and voltage divider ratio of SEC were measured. Freshly mounted preparations did not respond to luminal amiloride (10 microM), but within 2-3 h a significant response developed (delta Vt = 3.8 +/- 1.2 mV, delta Rt = 63 +/- 23 omega cm2, and delta Vb = -6.9 +/- 1.3 mV), indicating activation of an apical Na+ conductance in SEC. Using circuit analysis equations, we calculate that SEC contribute 10.4% to gt under control conditions and 13.0% after Na+ conductance activation. Histamine (0.1 mM), which stimulates the oxyntopeptic cells (OC), increased Vt and decreased Rt but did not significantly alter the membrane resistances of SEC. As a result, the contribution of SEC to gt fell to 7.4 or 9.3%, respectively. The data confirm that SEC are poorly permeable and that the major conductance path across gastric mucosa leads through OC in the glands. The reason for the protracted in vitro activation of the apical Na+ conductance in SEC is not known.

Membrane capacitance and conductance changes parallel mucin secretion in the human airway epithelium

2006 ◽  
Vol 290 (3) ◽  
pp. L558-L569 ◽  
Author(s):  
Henry Danahay ◽  
Hazel C. Atherton ◽  
Alan D. Jackson ◽  
James L. Kreindler ◽  
Christopher T. Poll ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Surface Area ◽  
Apical Membrane ◽  
Basolateral Membrane ◽  
Impedance Analysis ◽  
Membrane Resistance ◽  
Human Bronchial Epithelial Cells ◽  
Bronchial Epithelial ◽  
Conductance Changes ◽  
Kinetics Of

Measurement of the magnitude and kinetics of exocytosis from intact epithelia has historically been difficult. Using well-differentiated cultures of human bronchial epithelial cells, we describe the use of transepithelial impedance analysis to enable the real-time quantification of mucin secretagogue-induced changes in membrane capacitance (surface area) and conductance. ATPγS, UTP, ionomycin, and PMA induced robust increases in total cellular capacitance that were demonstrated to be dominated by a specific increase in apical membrane surface area. The UTP-induced increase in capacitance occurred in parallel with goblet cell emptying and the secretion of mucin and was associated with decreases in apical and basolateral membrane resistances. The magnitude and kinetics of the capacitance increases were dependent on the agonist and the sidedness of the stimulation. The peak increase in capacitance induced by UTP was ∼30 mucin granule fusions per goblet cell. Secretagogue-induced decreases in apical membrane resistance were independent of exocytosis, although each of the secretagogues induced profound reductions in basolateral membrane resistance. Transepithelial impedance analysis offers the potential to study morphological and conductance changes in cultured human bronchial epithelial cells.

Localization of Cl- conductance in normal and Cl- impermeability in cystic fibrosis sweat duct epithelium

1989 ◽  
Vol 257 (4) ◽  
pp. C727-C735 ◽  
Author(s):  
M. M. Reddy ◽  
P. M. Quinton
Keyword(s):  
Cystic Fibrosis ◽  
Basolateral Membrane ◽  
Voltage Divider ◽  
Sweat Duct ◽  
Basolateral Membranes ◽  
Duct Epithelium ◽  
Voltage Divider Ratio ◽  
Normal Duct ◽  
Cl Conductance ◽  
Cl Permeability

We studied the Cl- permeability properties of apical and basolateral membranes of human reabsorptive sweat duct (RSD) from normal and cystic fibrosis (CF) subjects. In normal ducts, Cl- substitution by impermeant anion gluconate in the lumen increased the voltage divider ratio (VDR) from 4.8 +/- 0.9 to 7.0 +/- 1.1 (n = 8, P less than 0.05), whereas Cl- substitution in the contraluminal bath decreased the VDR from 3.2 +/- 0.7 to 1.9 +/- 0.4 (n = 7, P less than 0.05). These results are consistent with a significant Cl- permeability in both apical and basolateral membranes of normal ducts. Amiloride (10(-4) M) in the lumen of normal ducts resulted in a small increase in VDR from 4.2 +/- 0.6 to 5.0 +/- 0.8 (n = 10, P less than 0.05), whereas the current-induced basolateral membrane voltage deflections (delta Vb) increased from 6.9 +/- 1.3 to 7.7 +/- 1.2 mV, suggesting that inhibition of Na+ permeability decreased basolateral membrane Cl- permeability. In the absence of luminal Cl-, amiloride decreased delta Vb and induced much greater effect on VDR (from 5.2 +/- 1.1 to 10.8 +/- 2.3, n = 9, P less than 0.05) than in the presence of Cl-. Likewise, in the presence of amiloride, Cl- substitution in the lumen had greater effect on VDR (increased from 3.5 +/- 0.5 0.5 to 10.0 +/- 1.5, n = 15, P less than 0.05) than in the absence of amiloride. These results indicate that Na+ conductance in the apical membrane of the normal duct is significantly smaller than Cl- conductance.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Nystatin as a probe for investigating the electrical properties of a tight epithelium.

1977 ◽  
Vol 70 (4) ◽  
pp. 427-440 ◽  
Author(s):  
S A Lewis ◽  
D C Eaton ◽  
C Clausen ◽  
J M Diamond
Keyword(s):  
Apical Membrane ◽  
Basolateral Membrane ◽  
Membrane Conductance ◽  
Voltage Divider ◽  
Junctional Conductance ◽  
Transepithelial Voltage ◽  
Almost All ◽  
Voltage Divider Ratio ◽  
Rabbit Urinary Bladder ◽  
Tight Epithelium

We show how the antibiotic nystatin may be used in conjunction with microelectrodes to resolve transepithelial conductance Gt into its components: Ga, apical membrane conductance; Gbl, basolateral membrane conductance; and Gj, junctional conductance. Mucosal addition of nystatin to rabbit urinary bladder in Na+-containing solutions caused Gt to increase severalfold to ca. 460 micrometerho/muF, and caused the transepithelial voltage Vt to approach +50 mV regardless of its initial value. From measurements of Gt and the voltage-divider ratio as a function of time after addition or removal of nystatin, values for Ga, Gbl, and Gj of untreated bladder could be obtained. Nystatin proved to have no direct effect on Gbl or Gj but to increase Ga by about two orders of magnitude, so that the basolateral membrane then provided almost all of the electrical resistance in the transcellular pathway. The nystatin channel in the apical membrane was more permeable to cations than to anions. The dose-response curve for nystatin had a slope of 4.6. Use of nystatin permitted assessment of whether microelectrode impalement introduced a significant shunt conductance into the untreated apical membrane, with the conclusion that such a shunt was negligible in the present experiments. Nystatin caused a hyperpolarization of the basolateral membrane potential in Na+-containing solutions. This may indicate that the Na+ pump in this membrane is electrogenic.

pH effects on basolateral membrane ion conductances in gallbladder epithelium

1989 ◽  
Vol 256 (6) ◽  
pp. C1184-C1195 ◽  
Author(s):  
J. S. Stoddard ◽  
L. Reuss
Keyword(s):  
Epithelial Cells ◽  
Basolateral Membrane ◽  
Potassium Conductance ◽  
Ph Effects ◽  
Small Decrease ◽  
Gallbladder Epithelium ◽  
Intracellular Microelectrodes ◽  
K Permeability ◽  
Ion Conductances ◽  
Cl Permeability

The pH sensitivity of the basolateral membrane voltage of Necturus gallbladder epithelial cells (Vcs) was evaluated with conventional and pH-sensitive intracellular microelectrodes. Elevating solution CO2 from 1 to 5% (at constant [HCO3-] = 10 mM) caused a depolarization of Vcs from -76 +/- 3 to -60 +/- 2 mV and a decrease in intracellular pH (pHi) from 7.36 +/- 0.04 to 7.05 +/- 0.03. Serosal exposure to a 50 mM HCO3(-)-5% CO2 solution [at constant extracellular pH (pHo)] caused a similar cell acidification (delta pHi = 0.27), whereas at 3 min Vcs was unchanged. Exposure to 1 mM HCO3- (at constant CO2) depolarized Vcs from -77 +/- 2 to -56 +/- 2 mV and caused a small decrease in pHi (from 7.36 +/- 0.03 to 7.33 +/- 0.03). These results indicate that the observed depolarizations of Vcs are attributable to changes in pHo and not in pHi. Basolateral membrane potassium conductance (GK) congruent to chloride conductance (GCl) congruent to 0.50 mS/cm2 in 10 mM HCO3(-)-1% CO2 Ringer. The depolarization of Vcs caused by elevation of serosal [K+] in 50 mM HCO3(-)-5% CO2 was similar to that observed under control conditions. In contrast, the depolarization of Vcs elicited by elevating serosal [K+] was reduced by about two-thirds in 1 mM HCO3-, whereas the depolarization caused by reduction of serosal [Cl-] was increased twofold in 1 mM HCO3-, compared with control. Inasmuch as the apparent ratio of membrane resistances remained unchanged during serosal solution acidification, the most likely explanation for the observed decrease in Vcs is a reduction of basolateral K+ permeability concomitant with an increase in Cl- permeability.

Microelectrode measurements from oxyntic cells in intact Necturus gastric mucosa

1985 ◽  
Vol 249 (5) ◽  
pp. C535-C540 ◽  
Author(s):  
J. R. Demarest ◽  
T. E. Machen
Keyword(s):  
Membrane Potential ◽  
Apical Membrane ◽  
Basolateral Membrane ◽  
Cell Types ◽  
Tenfold Increase ◽  
Simultaneous Decrease ◽  
K Concentration ◽  
Apical Membranes ◽  
Microelectrode Measurements ◽  
Cell Membrane Resistances

The electrical properties of oxyntic cells were measured in intact isolated Necturus fundic mucosa by dissecting away the serosal muscle and connective tissue and impaling the oxyntic cells across their basolateral membranes. Their properties under resting [i.e., not secreting acid (10(-4) M serosal cimetidine)] and stimulated (10(-4) M histamine) conditions were compared with those of surface cells impaled across their apical membranes in a separate set of experiments. Histamine hyperpolarized the transepithelial potential by 6-10 mV and reduced the transepithelial resistance by approximately 40%. The basolateral membrane potential (Vcs) of both cell types was significantly hyperpolarized by histamine, that of oxyntic cells from a resting value of -50 to -59 mV (P less than 0.001) and that of surface cells from -50 to -54 mV (P less than 0.05). Histamine also hyperpolarized the apical membrane potential (Vmc) of the oxyntic cells; however, the Vmc of surface cells was significantly depolarized. The ratio of the apical to basolateral cell membrane resistances Ra/Rb (delta Vmc/delta Vcs resulting from transepithelial current pulses) of resting oxyntic cells was 1.1 and that of surface cells was 3.6. Stimulation did not affect the Ra/Rb of either cell type. A tenfold increase in serosal K+ concentration depolarized Vcs and increased Ra/Rb of resting and stimulated oxyntic cells, indicating a significant basolateral K+ conductance. The results are consistent with a purely passive role for surface cells and indicate that stimulation results in a simultaneous decrease of both the apical and basolateral membrane resistances of the oxyntic cells.

scholarly journals Cell Swelling Activates the K+ Conductance and Inhibits the Cl− Conductance of the Basolateral Membrane of Cells from a Leaky Epithelium

1997 ◽  
Vol 109 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Ruben J. Torres ◽  
Muthangi Subramanyam ◽  
Guillermo A. Altenberg ◽  
Luis Reuss
Keyword(s):  
Epithelial Cells ◽  
Basolateral Membrane ◽  
Membrane Resistance ◽  
Cell Swelling ◽  
Free Calcium ◽  
Bathing Solution ◽  
Osmotic Swelling ◽  
Membrane Hyperpolarization ◽  
Intracellular Free Calcium Concentration ◽  
Free Calcium Concentration

Necturus gallbladder epithelial cells bathed in 10 mM HCO3/1% CO2 display sizable basolateral membrane conductances for Cl− (GClb) and K + (GKb). Lowering the osmolality of the apical bathing solution hyperpolarized both apical and basolateral membranes and increased the K +/Cl− selectivity of the basolateral membrane. Hyperosmotic solutions had the opposite effects. Intracellular free-calcium concentration ([Ca2+]i) increased transiently during hyposmotic swelling (peak at ∼30 s, return to baseline within ∼90 s), but chelation of cell Ca2+ did not prevent the membrane hyperpolarization elicited by the hyposmotic solution. Cable analysis experiments showed that the electrical resistance of the basolateral membrane decreased during hyposmotic swelling and increased during hyperosmotic shrinkage, whereas the apical membrane resistance was unchanged in hyposmotic solution and decreased in hyperosmotic solution. We assessed changes in cell volume in the epithelium by measuring changes in the intracellular concentration of an impermeant cation (tetramethylammonium), and in isolated polarized cells measuring changes in intracellular calcein fluorescence, and observed that these epithelial cells do not undergo measurable volume regulation over 10–12 min after osmotic swelling. Depolarization of the basolateral membrane voltage (Vcs) produced a significant increase in the change in Vcs elicited by lowering basolateral solution [Cl−], whereas hyperpolarization of Vcs had the opposite effect. These results suggest that: (a) Hyposmotic swelling increases GKb and decreases G Clb. These two effects appear to be linked, i.e., the increase in G Kb produces membrane hyperpolarization, which in turn reduces G Clb. ( b) Hyperosmotic shrinkage has the opposite effects on GKb and G Clb. ( c) Cell swelling causes a transient increase in [Ca2+]i, but this response may not be necessary for the increase in GKb during cell swelling.

Effect of Calcium on the Growth and Differentiation of Cultured Rat Esophageal Epithelial Cells

1982 ◽  
Vol 40 ◽  
pp. 132-133
Author(s):  
W.T. Gunning ◽  
M.R. Marino ◽  
M.S. Babcock ◽  
G.D. Stoner
Keyword(s):  
Epithelial Cells ◽  
Cell Types ◽  
Replication Rate ◽  
Enzymatic Dissociation ◽  
Growth Assay ◽  
Epidermal Growth ◽  
Fetal Bovine ◽  
Esophageal Epithelial Cells ◽  
Cellular Replication

The role of calcium in modulating cellular replication and differentiation has been described for various cell types. In the present study, the effects of Ca++ on the growth and differentiation of cultured rat esophageal epithelial cells was investigated.Epithelial cells were isolated from esophagi taken from 8 week-old male CDF rats by the enzymatic dissociation method of Kaighn. The cells were cultured in PFMR-4 medium supplemented with 0.25 mg/ml dialyzed fetal bovine serum, 5 ng/ml epidermal growth factor, 10-6 M hydrocortisone 10-6 M phosphoethanolamine, 10-6 M ethanolamine, 5 pg/ml insulin, 5 ng/ml transferrin, 10 ng/ml cholera toxin and 50 ng/ml garamycin at 36.5°C in a humidified atmosphere of 3% CO2 in air. At weekly intervals, the cells were subcultured with a solution containing 1% polyvinylpyrrolidone, 0.01% EGTA, and 0.05% trypsin. After various passages, the replication rate of the cells in PFMR-4 medium containing from 10-6 M to 10-3 M Ca++ was determined using a clonal growth assay.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

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