Effect of the thiol-oxidizing agent diamide on NH2Cl-induced rat colonic electrolyte secretion

1993 ◽  
Vol 265 (1) ◽  
pp. C166-C170 ◽  
Author(s):  
H. Tamai ◽  
J. F. Kachur ◽  
M. B. Grisham ◽  
M. W. Musch ◽  
E. B. Chang ◽  
...  
Keyword(s):  
Colonic Mucosa ◽  
Short Circuit ◽  
Chloride Ion ◽  
Short Circuit Current ◽  
Rat Colon ◽  
Maximal Effect ◽  
Oxidizing Agent ◽  
Maximal Increase ◽  
Ussing Chambers ◽  
Electrolyte Secretion

The granulocyte-derived oxidant, monochloramine (NH2Cl), is known to stimulate chloride ion secretion in rat distal colonic mucosa mounted in Ussing chambers, through mechanisms that are sensitive and insensitive to tetrodotoxin (TTX). The possible role of intracellular thiols, in the mechanism of action of NH2Cl as a secretagogue, was evaluated with the thiol-oxidizing agent diamide and by measuring tissue sulfhydryl levels in response to NH2Cl. Serosal exposure to the antioxidant glutathione (0.25 mM), 5 min before NH2Cl (50 microM) addition, decreased the maximal effect of 50 microM NH2Cl on short-circuit current (Isc). The NH2Cl-stimulated increase in Isc was not affected by mucosal amiloride (5 microM). Pretreatment with 0.1 mM diamide shortened the lag period before the increase in Isc in response to NH2Cl, but it did not affect the maximal increase in Isc. Although TTX (0.5 microM) increased the lag time for achievement of the maximal Isc response to NH2Cl, the neurotoxin did not inhibit the effect of diamide, suggesting that diamide acts primarily on the nonneural component of NH2Cl-stimulated secretion. Incubation of colonic mucosa with NH2Cl, with or without diamide, decreased cellular acid-soluble sulfhydryl concentrations. Taken together, the results support a role for epithelial cell thiols in NH2Cl-stimulated electrolyte secretion by the rat colon.

Neuromodulation of ion transport in porcine distal colon: NPY reduces secretory actions of leukotrienes

1995 ◽  
Vol 269 (2) ◽  
pp. R426-R431 ◽  
Author(s):  
T. R. Traynor ◽  
D. R. Brown ◽  
S. M. O'Grady
Keyword(s):  
Ion Transport ◽  
Colonic Mucosa ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Effective Concentration ◽  
Leukotriene C4 ◽  
Ussing Chambers ◽  
Cl Secretion ◽  
Half Maximal Effective Concentration

Electrical transmural stimulation (ETS) was used to examine the neuroregulation of electrolyte transport in the porcine distal colon. ETS of the colonic mucosa-submucosa mounted in Ussing chambers produced rapid and transient increases in short-circuit current (Isc) that were inhibited 36% by serosal bumetanide, suggesting that a portion of the response may be attributed to Cl secretion. ETS actions were dependent upon stimulus intensity and frequency and were inhibited by tetrodotoxin and omega-conotoxin. Prazosin and pyrilamine had no effect on the mucosal responses to ETS, whereas atropine reduced the responses by 32%. Neuropeptide Y (NPY) also reduced the mucosal responses to ETS up to 60% (half-maximal effective concentration = 17 nM). In addition, the effects of leukotriene C4, previously shown to stimulate Cl secretion via a neuronal pathway, were also inhibited by NPY. These results indicate that cholinergic submucosal neurons play a role in the regulation of epithelial ion transport and that NPY acts as an inhibitory neuromodulator, particularly on leukotriene-sensitive neurons in the porcine distal colon.

Alterations of the VIP-stimulated cAMP pathway in rat distal colon after abdominal irradiation

2002 ◽  
Vol 282 (5) ◽  
pp. G835-G843 ◽  
Author(s):  
E. Morel ◽  
I. Dublineau ◽  
F. Lebrun ◽  
N. M. Griffiths
Keyword(s):  
Short Circuit ◽  
Major Change ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Cell Number ◽  
Rat Colon ◽  
Camp Accumulation ◽  
Ussing Chambers ◽  
Abdominal Irradiation ◽  
Vip Receptor

Ionizing radiation induces hyporesponsiveness of rat colonic mucosa to vasoactive intestinal peptide (VIP). Possible mechanisms responsible for this hyporesponsiveness of the cAMP communication pathway in rat colon were investigated. VIP- and forskolin-stimulated short-circuit current ( I sc) responses were studied after a 10-Gy abdominal irradiation in Ussing chambers as well as in single, isolated crypts. Adenylyl cyclase (AC) activity and VIP receptor characteristics were determined in mucosal membrane preparations. In addition, alterations in crypt morphology were studied. Impaired secretory responses to VIP and forskolin were observed 4 days after irradiation (decrease of 80%). cAMP analog-stimulated I scresponses were unchanged. In isolated crypts, VIP- and forskolin-stimulated cAMP accumulation was markedly reduced by 80 and 50%, respectively. VIP-stimulated AC activity and VIP receptor number were decreased in membrane preparations. No major change of cellularity was associated with these functional alterations. In conclusion, the decreased secretory responses to VIP of rat colon are associated with reduced cAMP accumulation, decreased AC activity, and diminution of VIP receptor numbers without a marked decrease of crypt cell number.

Expression of the chloride channel ClC-2 in the murine small intestine epithelium

2000 ◽  
Vol 279 (6) ◽  
pp. C1787-C1794 ◽  
Author(s):  
Katalin Gyömörey ◽  
Herman Yeger ◽  
Cameron Ackerley ◽  
Elizabeth Garami ◽  
Christine E. Bear
Keyword(s):  
Small Intestine ◽  
Chloride Channel ◽  
Chloride Transport ◽  
Short Circuit ◽  
Chloride Ion ◽  
Short Circuit Current ◽  
Chloride Secretion ◽  
Ussing Chambers ◽  
Dependent Change ◽  
Knockout Animals

The chloride channel ClC-2 has been implicated in neonatal airway chloride secretion. To assess its role in secretion by the small intestine, we assessed its subcellular expression in ileal segments obtained from mice and studied the chloride transport properties of this tissue. Chloride secretion across the mucosa of murine ileal segments was assessed in Ussing chambers as negative short-circuit current ( Isc). If ClC-2 contributed to chloride secretion, we predicted on the basis of previous studies that negative Iscwould be stimulated by dilution of the mucosal bath and that this response would depend on chloride ion and would be blocked by the chloride channel blocker 5-nitro-2-(3-phenylpropylamino) benzoic acid but not by DIDS. In fact, mucosal hypotonicity did stimulate a chloride-dependent change in Iscthat exhibited pharmacological properties consistent with those of ClC-2. This secretory response is unlikely to be mediated by the cystic fibrosis transmembrane conductance regulator (CFTR) channel because it was also observed in CFTR knockout animals. Assessment of the native expression pattern of ClC-2 protein in the murine intestinal epithelium by confocal and electron microscopy showed that ClC-2 exhibits a novel distribution, a distribution pattern somewhat unexpected for a channel involved in chloride secretion. Immunolabeled ClC-2 was detected predominantly at the tight junction complex between adjacent intestinal epithelial cells.

Adaptation of stress-induced mucosal pathophysiology in rat colon involves opioid pathways

2001 ◽  
Vol 281 (1) ◽  
pp. G124-G128 ◽  
Author(s):  
Derrick A. Yates ◽  
Javier Santos ◽  
Johan D. Söderholm ◽  
Mary H. Perdue
Keyword(s):  
Acute Stress ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Rat Colon ◽  
Opioid Antagonists ◽  
Adaptive Responses ◽  
Ussing Chambers ◽  
Ion Secretion ◽  
Mucosal Changes ◽  
Wistar Kyoto

Acute stress increases ion secretion and permeability of rat colonic epithelium. However, it is not known if stress-induced mucosal changes are subject to adaptation. Wistar-Kyoto rats were exposed to either continuous water-avoidance stress (CS) for 60 min or intermittent stress (IS) for three 20-min periods. Distal colonic segments were mounted in Ussing Chambers, and ion-transport [short-circuit current ( I sc)] and permeability [conductance and flux of horseradish peroxidase (HRP)] parameters were measured. CS significantly increased I sc, conductance, and HRP flux compared with control values. In contrast, in IS rats these variables were similar to those in nonstressed controls. To study the pathways involved in IS-induced adaptation, rats were pretreated intraperitoneally with the opioid antagonists naloxone or methylnaloxone. Opioid antagonists had no effect on values in control or CS rats. However, in the IS group, naloxone and methylnaloxone reversed the adaptive responses, and all variables increased to CS values. We conclude that stress-induced colonic mucosal pathophysiology is subject to rapid adaptation, which involves opioid pathways.

Effect of sorbin on electrolyte transport in rat and human intestine

1999 ◽  
Vol 276 (1) ◽  
pp. G107-G114 ◽  
Author(s):  
Bruno Eto ◽  
Michel Boisset ◽  
Bertrand Griesmar ◽  
Jehan-François Desjeux
Keyword(s):  
Water Absorption ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrolyte Transport ◽  
Secretory Diarrhea ◽  
Maximal Effect ◽  
Human Intestine ◽  
Ussing Chambers ◽  
Antisecretory Effect ◽  
Dose Dependent

Stimulating water absorption in the colon represents an important target to reduce stool output in secretory diarrhea. Recently, a 153-amino-acid peptide was isolated from porcine upper small intestine and purified, taking into account the increase of water absorption in guinea pig gallbladder. Accordingly, this peptide was named sorbin. The aim of the present study was to determine if the COOH-terminal heptapeptide of sorbin (C7-sorbin) participates in the regulation of electrolyte transport in the colon. Different regions (from duodenum to colon) of stripped intestinal mucosa from rats or humans were mounted in Ussing chambers to measure the changes in short-circuit current (Δ Isc) and net22Na and36Cl fluxes ([Formula: see text] and[Formula: see text]) after serosal exposure of 10−7to 10−3M C7-sorbin. In fasted rat intestine, C7-sorbin (10−4M) induced an immediate reduction in Iscin the distal ileum and proximal and distal colon but not in the duodenum and jejunum. In the colon, Iscreduction and[Formula: see text] and[Formula: see text] stimulation were dose dependent (EC50= 2 × 10−5M). At 10−3M, maximal effect was observed (Δ Isc= −1.14 ± 0.05, Δ[Formula: see text] = +4.97 ± 1.38, and Δ[Formula: see text] = +9.25 ± 1.44 μeq ⋅ h−1⋅ cm−2). C7-sorbin (10−3M) inhibited the increase in Iscinduced by a series of 10 secretory agents such as secretin, vasoactive intestinal peptide, PGE2, and serotonin. In HT-29-Cl19A cells, C7-sorbin induced an increase in Isc, with a maximal effect at 10−3M (Δ Isc= 0.29 ± 0.10 μeq ⋅ h−1⋅ cm−2). In human intestine, a dose-dependent decrease in Iscwas observed in right and sigmoid colons in basal and stimulated conditions (EC50≅ 10−5M; at 10−4M, Δ Isc= −2.66 ± 0.17 μeq ⋅ h−1⋅ cm−2) but not in the jejunum. The results indicate that C7-sorbin stimulated NaCl neutral absorption and inhibited electrogenic Cl−in rat and human intestinal epithelia. In addition, the antisecretory effect was essentially observed in the distal part of both rat and human intestine and the magnitude of the proabsorptive effect was directly related to the magnitude of the previously induced secretion.

scholarly journals The TRPA1 Agonist Cinnamaldehyde Induces the Secretion of HCO3− by the Porcine Colon

2021 ◽  
Vol 22 (10) ◽  
pp. 5198
Author(s):  
David Manneck ◽  
Gisela Manz ◽  
Hannah-Sophie Braun ◽  
Julia Rosendahl ◽  
Friederike Stumpff
Keyword(s):  
Inflammatory Bowel Disease ◽  
Gastrointestinal Tract ◽  
Patch Clamp ◽  
Bowel Disease ◽  
Colonic Mucosa ◽  
Therapeutic Potential ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Ussing Chambers ◽  
Inflammatory Bowel

A therapeutic potential of the TRPA1 channel agonist cinnamaldehyde for use in inflammatory bowel disease is emerging, but the mechanisms are unclear. Semi-quantitative qPCR of various parts of the porcine gastrointestinal tract showed that mRNA for TRPA1 was highest in the colonic mucosa. In Ussing chambers, 1 mmol·l−1 cinnamaldehyde induced increases in short circuit current (ΔIsc) and conductance (ΔGt) across the colon that were higher than those across the jejunum or after 1 mmol·l−1 thymol. Lidocaine, amiloride or bumetanide did not change the response. The application of 1 mmol·l−1 quinidine or the bilateral replacement of 120 Na+, 120 Cl− or 25 HCO3− reduced ΔGt, while the removal of Ca2+ enhanced ΔGt with ΔIsc numerically higher. ΔIsc decreased after 0.5 NPPB, 0.01 indometacin and the bilateral replacement of 120 Na+ or 25 HCO3−. The removal of 120 Cl− had no effect. Cinnamaldehyde also activates TRPV3, but comparative measurements involving patch clamp experiments on overexpressing cells demonstrated that much higher concentrations are required. We suggest that cinnamaldehyde stimulates the secretion of HCO3− via apical CFTR and basolateral Na+-HCO3− cotransport, preventing acidosis and damage to the epithelium and the colonic microbiome. Signaling may involve the opening of TRPA1, depolarization of the epithelium and a rise in PGE2 following a lower uptake of prostaglandins via OATP2A1.

scholarly journals Distinct K+ conductive pathways are required for Cl− and K+ secretion across distal colonic epithelium

2006 ◽  
Vol 291 (4) ◽  
pp. C636-C648 ◽  
Author(s):  
Susan Troutman Halm ◽  
Tianjiang Liao ◽  
Dan R. Halm
Keyword(s):  
Colonic Mucosa ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Rat Colon ◽  
Colonic Epithelium ◽  
High Concentration ◽  
K Secretion ◽  
Synergistic Response ◽  
High Concentrations ◽  
Apical Membranes

Secretion of Cl− and K+ in the colonic epithelium operates through a cellular mechanism requiring K+ channels in the basolateral and apical membranes. Transepithelial current [short-circuit current ( Isc)] and conductance ( Gt) were measured for isolated distal colonic mucosa during secretory activation by epinephrine (Epi) or PGE2 and synergistically by PGE2 and carbachol (PGE2 + CCh). TRAM-34 at 0.5 μM, an inhibitor of KCa3.1 (IK, Kcnn4) K+ channels (H. Wulff, M. J. Miller, W. Hänsel, S. Grissmer, M. D. Cahalan, and K. G. Chandy. Proc Natl Acad Sci USA 97: 8151–8156, 2000), did not alter secretory Isc or Gt in guinea pig or rat colon. The presence of KCa3.1 in the mucosa was confirmed by immunoblot and immunofluorescence detection. At 100 μM, TRAM-34 inhibited Isc and Gt activated by Epi (∼4%), PGE2 (∼30%) and PGE2 + CCh (∼60%). The IC50 of 4.0 μM implicated involvement of K+ channels other than KCa3.1. The secretory responses augmented by the K+ channel opener 1-EBIO were inhibited only at a high concentration of TRAM-34, suggesting further that KCa3.1 was not involved. Sensitivity of the synergistic response (PGE2 + CCh) to a high concentration TRAM-34 supported a requirement for multiple K+ conductive pathways in secretion. Clofilium (100 μM), a quaternary ammonium, inhibited Cl− secretory Isc and Gt activated by PGE2 (∼20%) but not K+ secretion activated by Epi. Thus Cl− secretion activated by physiological secretagogues occurred without apparent activity of KCa3.1 channels but was dependent on other types of K+ channels sensitive to high concentrations of TRAM-34 and/or clofilium.

Stimulation of chloride secretion by baicalein in isolated rat distal colon

2002 ◽  
Vol 282 (3) ◽  
pp. G508-G518 ◽  
Author(s):  
W. H. Ko ◽  
V. W. Y. Law ◽  
W. C. Y. Yip ◽  
G. G. L. Yue ◽  
C. W. Lau ◽  
...  
Keyword(s):  
Colonic Mucosa ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Chloride Secretion ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Ussing Chambers ◽  
Rat Distal Colon ◽  
Cystic Fibrosis Transmembrane

The effect of baicalein on mucosal ion transport in the rat distal colon was investigated in Ussing chambers. Mucosal addition of baicalein (1–100 μM) elicited a concentration-dependent short-circuit current ( I sc) response. The increase in I sc was mainly due to Cl−secretion. The presence of mucosal indomethacin (10 μM) significantly reduced both the basal and subsequent baicalein-evoked I sc responses. The baicalein-induced I sc were inhibited by mucosal application of diphenylamine-2-carboxylic acid (100 μM) and glibenclamide (500 μM) and basolateral application of chromanol 293B (30 μM), a blocker of KvLQT1 channels and Ba2+ ions (5 mM). Treatment of the colonic mucosa with baicalein elicited a threefold increase in cAMP production. Pretreating the colonic mucosa with carbachol (100 μM, serosal) but not thapsigargin (1 μM, both sides) abolished the baicalein-induced I sc. Addition of baicalein subsequent to forskolin induced a further increase in I sc. These results indicate that the baicalein evoked Cl− secretion across rat colonic mucosa, possibly via a cAMP-dependent pathway. However, the action of baicalein cannot be solely explained by its cAMP-elevating effect. Baicalein may stimulate Cl− secretion via a cAMP-independent pathway or have a direct effect on cystic fibrosis transmembrane conductance regulator.

Potassium secretion by rabbit descending colon: effects of adrenergic stimuli

1986 ◽  
Vol 250 (4) ◽  
pp. G432-G439 ◽  
Author(s):  
P. L. Smith ◽  
R. D. McCabe
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Maximal Effect ◽  
Dependent Manner ◽  
Adrenergic Stimulation ◽  
Adrenergic Agents ◽  
Ussing Chambers ◽  
K Secretion ◽  
Potassium Secretion

Stripped rabbit distal colonic mucosa was studied in vitro in Ussing chambers to investigate the effects of adrenergic stimuli on Na+, K+, and Cl- transport. The adrenergic stimuli epinephrine and norepinephrine decrease short-circuit current in a dose-dependent manner, with a half-maximal effect at 5 X 10(-7) M and a maximal effect between 10(-5) and 10(-4) M. The effects produced by norepinephrine and epinephrine can also be elicited by the beta 1-agonist dobutamine, but not by the beta 2-agonist terbutaline or the alpha-agonist phenylephrine. In addition, the effects of adrenergic stimulation can be inhibited by the beta-antagonist propranolol but not by the muscarinic antagonist atropine, the alpha 2-antagonist yohimbine, or tetrodotoxin. The decrease in short-circuit current elicited by adrenergic stimuli is accompanied by an increase in net K+ secretion with no change in net Cl- or Na+ transport. This increase in net K+ secretion elicited by beta-adrenergic stimulation can be inhibited by trifluoperazine but not by indomethacin. These studies suggest that K+ transport by the colon can be regulated by adrenergic agents acting via beta 1-receptors.

Inhibition of VIP-stimulated ion transport by a novel Y-receptor phenotype in rabbit distal colon

1993 ◽  
Vol 264 (5) ◽  
pp. G848-G854 ◽  
Author(s):  
G. H. Ballantyne ◽  
J. R. Goldenring ◽  
F. X. Fleming ◽  
S. Rush ◽  
J. S. Flint ◽  
...  
Keyword(s):  
Ion Transport ◽  
Colonic Mucosa ◽  
Peptide Yy ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Ussing Chambers ◽  
Potent Inhibition ◽  
Colonic Secretion ◽  
Receptor Phenotype

Neurocrine, endocrine, and paracrine regulators are critical to the control of colonic secretion. These studies have investigated the inhibition of vasoactive intestinal polypeptide (VIP)-stimulated ion transport by peptide YY (PYY) and other Y-class effectors in rabbit distal colonic mucosa mounted in Ussing chambers. PYY decreased basal short-circuit current (Isc) but did not significantly change either basal Na+ or Cl- flux. PYY inhibited VIP-stimulated increases in Isc by up to 86% and abolished VIP-induced Cl- secretion. PYY decreased VIP-generated increases in Isc by a tetrodotoxin-insensitive mechanism. PYY inhibited cholera toxin-stimulated as well as forskolin-stimulated increases in Isc but failed to alter stimulation by 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP). PYY decreased VIP-stimulated increases in tissue cAMP by 88% and forskolin-stimulated increases by 84%. PYY, neuropeptide Y (NPY), (Leu31,Pro34)-NPY, and pancreatic polypeptide (PP) all demonstrated potent inhibition of VIP-stimulated increases in Isc. PYY-(13-36) demonstrated little effect on VIP stimulation. Thus the rabbit distal colon possesses a novel Y-class receptor phenotype that demonstrates high affinity for all three PP-fold peptides, NPY, PYY, and PP.

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