Substance P-evoked Cl−secretion in guinea pig distal colonic epithelia: interaction with PGE2

2002 ◽  
Vol 283 (2) ◽  
pp. G347-G356 ◽  
Author(s):  
Yutaka Hosoda ◽  
Shin-Ichiro Karaki ◽  
Yukiko Shimoda ◽  
Atsukazu Kuwahara
Keyword(s):  
Substance P ◽  
Guinea Pig ◽  
Imaging System ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Intracellular Camp ◽  
Bathing Solution ◽  
Flux Chamber ◽  
Intracellular Ca

Interaction between substance P (SP) and PGE2on Cl−secretion in the guinea pig distal colonic epithelia was investigated. A short-circuit current ( Isc) was measured as an index of ion transport. Mucosa preparations deprived of muscle and submucosa of distal colon were mounted in the Ussing flux chamber and treated with TTX and piroxicam to remove the influences of neuronal activity and endogenous PG synthesis, respectively. Although SP (10−7M) itself evoked little increase in Isc, exogenous PGE2concentration dependently enhanced the response of SP. The effect of PGE2on the SP-evoked response was mimicked by forskolin and 8-bromoadenosine cAMP. Depletion of Ca2+from the bathing solution reduced the PGE2-dependent response of SP. Effects of PGE2, SP, and SP in the presence of PGE2on intracellular Ca2+concentration ([Ca2+]i) in isolated crypt cells were measured by the confocal microscope fluorescence imaging system. SP, but not PGE2, temporally evoked an increase in [Ca2+]ibut declined to the baseline within 3 min. A return of the SP-evoked increase in [Ca2+]iwas slower in the presence of PGE2than SP alone. These results suggest that PGE2synergistically enhances SP-evoked Cl−secretion via an interaction between the intracellular cAMP and [Ca2+]iin the epithelial cells. In conclusion, SP and PGE2could cooperatively induce massive Cl−secretion in guinea pig distal colon at epithelial levels.

Alterations in capsaicin-evoked electrolyte transport during the evolution of guinea pig TNBS ileitis

2002 ◽  
Vol 282 (6) ◽  
pp. G972-G980 ◽  
Author(s):  
Paula Miceli ◽  
Gerald P. Morris ◽  
Wallace K. MacNaughton ◽  
Stephen Vanner
Keyword(s):  
Substance P ◽  
Guinea Pig ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrolyte Transport ◽  
Secretory Function ◽  
Trinitrobenzenesulfonic Acid ◽  
Ussing Chambers ◽  
Circulating Cytokines

The efferent secretomotor activity of capsaicin-sensitive nerves was monitored during the evolution of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced ileitis in the guinea pig by recording changes in short-circuit current (Δ I sc) in response to capsaicin, substance P (SP), and carbachol. Submucosal-mucosal preparations mounted in standard Ussing chambers were studied at time 0, at 8 h, and 1, 3, 5, 7, 14, and 30 days following the intraluminal instillation of TNBS or saline. Maximal Δ I scresponses to capsaicin were dramatically attenuated (54%) by 24 h. By day 7, SP- and TTX-insensitive carbachol-stimulated Δ I sc were also significantly reduced. Similar attenuation in capsaicin and carbachol responses was observed in jejunal tissue 20 cm proximal to the inflamed site at day 7. These studies demonstrate that efferent secretomotor function of capsaicin-sensitive nerves is maintained early in TNBS ileitis but significantly reduced by 24 h. By day 7, defects in enterocyte secretory function at inflamed and noninflamed sites also occurred, an effect that may be mediated by circulating cytokines.

Substance P as a mediator of colonic secretory reflexes

1997 ◽  
Vol 272 (2) ◽  
pp. G238-G245 ◽  
Author(s):  
H. J. Cooke ◽  
M. Sidhu ◽  
P. Fox ◽  
Y. Z. Wang ◽  
E. M. Zimmermann
Keyword(s):  
Substance P ◽  
Messenger Rna ◽  
Short Circuit ◽  
Chronic Administration ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Chloride Secretion ◽  
Intestinal Epithelial ◽  
Axon Reflex ◽  
Reflex Pathways

The role of substance P in neural reflex pathways activated by stroking was investigated in muscle-stripped segments of distal colon from guinea pigs. Stroking the mucosal surface with a brush at 1 stroke/s evoked an increase in short-circuit current (Isc) indicative of chloride secretion. The response to mucosal stroking was maximally reduced by 69-75% by the antagonist GR-82334. The agonist [Sar9,Met(O2)11] substance P caused a bumetanide-sensitive increase in Isc when added to the mucosal or serosal bath. Ablation of extrinsic afferents with acute or chronic administration of capsaicin did not alter the mucosal stroking response. Reverse transcription-polymerase chain reaction and in situ hybridization revealed the presence of neurokinin1 (NK1) receptor messenger RNA in isolated colonocytes or crypt glands. Ligand binding of 125I-Bolton-Hunter-labeled substance P was inhibited by GR-82334. The 50% inhibitory concentration was 0.84 nM. The results demonstrate a role for substance P released from capsaicin-insensitive submucosal neurons and in mucosal stroking reflexes. The presence of NK1 receptors on isolated colonocytes suggests that appropriate elements are present for axon reflex activation of intestinal epithelial cells.

5-HT activates nitric oxide-generating neurons to stimulate chloride secretion in guinea pig distal colon

1998 ◽  
Vol 275 (4) ◽  
pp. G829-G834 ◽  
Author(s):  
Atsukazu Kuwahara ◽  
Hirofumi Kuramoto ◽  
Makoto Kadowaki
Keyword(s):  
Nitric Oxide ◽  
Guinea Pig ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Chloride Secretion ◽  
Evoked Response ◽  
Evoked Responses ◽  
No Donor ◽  
Simultaneous Application

The participation of nitric oxide (NO) in serotonin (5-hydroxytryptamine; 5-HT)-evoked chloride secretion in guinea pig distal colon was examined. Submucosal/mucosal segments were mounted in Ussing flux chambers, and an increase in short-circuit current ( I sc) was used as an index of secretion. Addition of 5-HT to the serosal side produced a concentration-dependent (10−7–10−5M) increase in I sc caused by chloride secretion. N G-nitro-l-arginine (l-NNA) significantly reduced the 5-HT-evoked early (P-1) and late (P-2) responses to 61.1 and 70.6% of control, respectively. Neurally evoked response was also inhibited by l-NNA. The NO donor sodium nitroprusside (SNP, 10−4 M) increased basal I sc mainly because of chloride secretion. The SNP-evoked response was significantly reduced by tetrodotoxin but was unchanged by atropine or indomethacin. These results suggest that the 5-HT-evoked increase in I sc is associated with an NO-generating mechanism. Atropine significantly reduced the 5-HT (10−5 M)-evoked P-1 and P-2 responses to 71.8 and 19.7% of control, respectively. Simultaneous application of atropine andl-NNA further decreased the 5-HT-evoked responses more than either drug alone; application ofl-NNA and atropine decreased the 5-HT-evoked P-1 and P-2 responses to 68.5 and 39.2% of atropine-treated tissues, respectively. These results suggest that noncholinergic components of P-1 and P-2 responses are 71.8 and 19.7% of control, respectively, and that NO components of P-1 and P-2 responses are 32 and 61%, respectively, of the noncholinergic component of the 5-HT-evoked responses. The results provide evidence that NO may participate as a noncholinergic mediator of 5-HT-evoked chloride secretion in guinea pig distal colon.

Effects of the inflammatory mediator prostaglandin D2 on submucosal neurons and secretion in guinea pig colon

1994 ◽  
Vol 266 (1) ◽  
pp. G132-G139 ◽  
Author(s):  
T. Frieling ◽  
C. Rupprecht ◽  
A. B. Kroese ◽  
M. Schemann
Keyword(s):  
Guinea Pig ◽  
Ganglion Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Chloride Secretion ◽  
Prostaglandin D2 ◽  
Flux Chamber ◽  
Dose Dependent Increase ◽  
Dose Dependent

Conventional flux chamber and intracellular recording methods were used to investigate the mode of action of prostaglandin D2 (PGD2) on ion transport in muscle-stripped segments of guinea pig colon and on colonic submucosal ganglion cells. Application of PGD2 resulted in a dose-dependent increase in short-circuit current that was reduced by serosal addition of bumetanide, tetrodotoxin, atropine, or piroxicam, but not hexamethonium. Application of PGD2 to submucosal neurons evoked a depolarization of the membrane potential that was associated with an enhanced spike discharge. In AH/type 2 neurons, postspike afterhyperpolarizations were reduced in amplitude and duration. The depolarizing responses to PGD2 were not affected by tetrodotoxin, indicative of a direct effect of PGD2 on the impaled neurons. Whereas fast excitatory postsynaptic potentials (EPSPs) were not affected by PGD2, slow EPSPs were reduced by a presynaptic effect, indicating presynaptic suppression of noncholinergic neurotransmitter release. The study demonstrates that PGD2 acts as a neuromodulator to evoke nerve-mediated chloride secretion, predominantly through activation of cholinergic submucosal neurons. The results further indicate that PGD2 released from lamina propria immune cells during antigenic stimulation may influence mucosal function by altering electrical behavior of submucosal neurons.

scholarly journals A primary culture of guinea pig gallbladder epithelial cells that is responsive to secretagogues

2000 ◽  
Vol 279 (5) ◽  
pp. G866-G874 ◽  
Author(s):  
Pamela J. Gunter-Smith ◽  
Oluwakemi Abdulkadir ◽  
Latanya Hammonds-Odie ◽  
Mary Scanlon ◽  
Raquel Terrell
Keyword(s):  
Cell Culture ◽  
Epithelial Cells ◽  
Guinea Pig ◽  
Ion Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Intestinal Epithelia ◽  
Intracellular Ca ◽  
A Cell ◽  
Transport Inhibitors

We have developed a cell culture of guinea pig gallbladder epithelial cells with which to study ion transport. When grown on permeable supports, the cultured epithelia developed a transepithelial resistance ( R t) of ∼500 Ω · cm2. The epithelial cell origin of the cell culture was further confirmed by immunocytochemical localization of cytokeratin. Ionomycin and forskolin increased transepithelial voltage and short-circuit current ( I sc) and decreased R t. The response to ionomycin was transient, whereas that to forskolin was sustained. Both were attenuated by replacement of Cl− and/or HCO3 −. Mucosal addition of the anion transport inhibitors DIDS or diphenylamine-2-carboxylic acid (DPC) blocked the response to ionomycin. The response to forskolin was blocked by DPC but not by DIDS. Ionomycin, but not forskolin, increased intracellular Ca2+ concentration in fura 2-loaded cells. PGE2, histamine, vasoactive intestinal polypeptide, and secretin elicited a sustained increase in I sc. Responses to ATP and CCK were transient. Thus cultured guinea pig gallbladder epithelia display the range of responses observed in the native tissue and are an appropriate model for studies of ion transport in gallbladder and intestinal epithelia.

Regulation of K secretion across the porcine gallbladder epithelium

1993 ◽  
Vol 264 (6) ◽  
pp. C1542-C1549 ◽  
Author(s):  
M. D. DuVall ◽  
S. M. O'Grady
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
K Channel ◽  
Intracellular Camp ◽  
Channel Blockers ◽  
Gallbladder Epithelium ◽  
K Channels ◽  
Ussing Chambers ◽  
Intracellular Ca ◽  
K Secretion

Porcine gallbladder epithelium from the neck and the fundus of the organ was stripped of serosal muscle and mounted in Ussing chambers to investigate the mechanisms of K secretion. The sensitivity to K channel blockers and regulation by norepinephrine (NE), adenosine 3',5'-cyclic monophosphate (cAMP), and increases in intracellular Ca concentration ([Ca]) were studied. The porcine gallbladder secretes K (approximately 0.8 mu eq/cm2.h) under basal conditions. Mucosal tetraethylammonium (TEA) produced a concentration-dependent increase in short-circuit current (Isc) and inhibited the unidirectional serosal-to-mucosal 86Rb flux JsmRb, resulting in a > 60% reduction in net Rb secretion. In contrast, serosal Ba produced a concentration-dependent decrease in Isc and stimulated JsmRb, resulting in a > 200% increase in net Rb secretion. NE inhibited JsmRb and net Rb secretion in both regions. In the fundic region the mucosal-to-serosal Rb flux (JmsRb) was also significantly increased, suggesting that active K absorption was activated. Exogenous cAMP increased JsmRb and net Rb secretion by > 85% in both regions. This increase in net Rb secretion was blocked by mucosal TEA but unaffected by NE. The Ca ionophore ionomycin also increased JsmRb and net Rb secretion and reduced the Isc by approximately 50%. Neither mucosal TEA nor Ba blocked changes in steady-state Rb secretion induced by ionomycin. Although both serosal Ba and ionomycin produced significant reductions in Isc, the effects of Ba were blocked by ionomycin pretreatment. These findings indicate that basal K secretion occurs through TEA-sensitive apical K channels and is regulated by intracellular cAMP. NE likely reduces K secretion by decreasing intracellular concentration of cAMP.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholinergic ion secretion in human colon requires coactivation by cAMP

1998 ◽  
Vol 275 (6) ◽  
pp. G1274-G1281 ◽  
Author(s):  
M. Mall ◽  
M. Bleich ◽  
M. Schürlein ◽  
J. Kühr ◽  
H. H. Seydewitz ◽  
...  
Keyword(s):  
Short Circuit ◽  
Ussing Chamber ◽  
Short Circuit Current ◽  
Human Colon ◽  
Intracellular Camp ◽  
Camp Production ◽  
Ion Secretion ◽  
Negative Current ◽  
Intracellular Ca ◽  
Second Messenger Pathways

Cl−secretion in the colon can be activated by an increase of either intracellular Ca2+ or cAMP. In this study we examined a possible interdependence of the two second-messenger pathways in human colonic epithelium. When measured in a modified Ussing chamber, carbachol (CCH; 100 μmol/l, basolateral), via an increase in cytosolic Ca2+concentration ([Ca2+]i), activated a transient lumen-negative equivalent short-circuit current ( I sc) [change (Δ) in I sc = −79.4 ± 7.5 μA/cm2]. Previous studies indicated that intracellular Ca2+ directly acts on basolateral K+ channels, thus enhancing driving force for luminal Cl− exit. Increased intracellular cAMP (by basolateral addition of 100 μmol/l IBMX and 1 μmol/l forskolin) activated a sustained lumen-negative current (Δ I sc = −42.4 ± 7.2 μA/cm2) that was inhibited by basolateral trans-6-cyano-4-( N-ethylsulfonyl- N-methylamino)-3-hydroxy-2,2-dimethyl&2-chromane (10 μmol/l), a blocker of KvLQT1 channels. In the presence of elevated cAMP, the CCH-activated currents were augmented (Δ I sc = 167.7 ± 32.7 μA/cm2), suggesting cooperativity of the Ca2+- and cAMP-mediated responses. Inhibition of endogenous cAMP production by indomethacin (10 μmol/l) significantly reduced CCH-activated currents and even reversed the polarity in 70% of the experiments. The transient lumen-positive I sc was probably due to activation of apical K+channels because it was blocked by luminal Ba2+ (5 mmol/l) and tetraethylammonium (10 mmol/l). In the presence of indomethacin (10 μmol/l, basolateral), an increase of cAMP activated a sustained negative I sc. Under these conditions, CCH induced a large further increase in lumen-negative I sc(Δ I sc = −100.0 ± 21.0 μA/cm2). We conclude that CCH acting via [Ca2+]ican induce Cl− secretion only in the presence of cAMP, i.e., when luminal Cl− channels are already activated. The activation of a luminal and basolateral K+ conductance by CCH may be essential for transepithelial KCl secretion in human colon.

H2 receptors mediate cyclical chloride secretion in guinea pig distal colon

1990 ◽  
Vol 258 (6) ◽  
pp. G887-G893 ◽  
Author(s):  
Y. Z. Wang ◽  
H. J. Cooke
Keyword(s):  
Guinea Pig ◽  
Chloride Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Chloride Secretion ◽  
Chloride Ions ◽  
H2 Antagonist ◽  
H2 Receptors ◽  
Peak Increase

We tested the hypothesis that histamine mediates ion secretion in the guinea pig distal colon by stimulating H2 receptors on submucosal neurons. Serosal addition of histamine evoked a transient increase in short-circuit current (Isc) followed by recurrent cyclical increases in Isc. The transient phase of the response was examined previously and was not investigated in these studies. Histamine (1.5-2.5 x 10(-5) M) evoked a peak increase in Isc of 177 +/- 25 microA/cm2 at intervals of 5 min for 1-2 h. The duration of each recurrent cycle averaged 2.1 +/- 0.3 min. The H2 agonist dimaprit evoked recurrent cycles that had larger amplitudes than those caused by histamine. In the presence of histamine or dimaprit, the amplitude of the first cycle of the response was always less than subsequent cycles, regardless of the initial concentration. The cyclical responses to histamine, 2-methylhistamine, or dimaprit were unaltered by the H1 blocker pyrilamine, were reduced by the H2 antagonist cimetidine, and were abolished by the neuronal blocker tetrodotoxin. Blockade of prostaglandin formation with piroxicam did not prevent the recurrent cycles. The recurrent cycles were inhibited by the chloride transport blocker bumetanide and by removal of chloride ions. Our results demonstrate that histamine mediates prolonged cyclical chloride secretion in the guinea pig distal colon by activating H2 receptors on submucosal neurons involved in regulation of epithelial chloride transport.

Aldosterone stimulates K secretion prior to onset of Na absorption in guinea pig distal colon

1994 ◽  
Vol 266 (2) ◽  
pp. C552-C558 ◽  
Author(s):  
D. R. Halm ◽  
S. T. Halm
Keyword(s):  
Guinea Pig ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Ussing Chambers ◽  
High Affinity Receptor ◽  
Additive Increase ◽  
K Secretion ◽  
Affinity Receptor

Distal colon from guinea pig was stimulated in vitro by aldosterone in Ussing chambers that allowed measurement of short-circuit current (Isc) and tissue conductance (Gt). The response to aldosterone was delayed by approximately 20 min and resulted in a negative Isc, consistent with K secretion. Approximately 1 h later the Isc began to increase and eventually became positive, consistent with subsequent stimulation of Na absorption. The Na-absorptive response could be inhibited by mucosal amiloride without altering the rate of K secretion. Similarly, K secretion could be inhibited by serosal bumetanide without altering Na absorption. In the presence of spironolactone, actinomycin D, or cycloheximide, aldosterone failed to stimulate both K secretion and Na absorption. A dose response to aldosterone provided an apparent Kd of 2.6 +/- 0.5 nM, consistent with a high-affinity receptor coupled to this secretory response. Stimulation by the K secretagogue epinephrine did not produce an additive increase in K secretion, suggesting that the same cell type responds to both aldosterone and epinephrine and that the protein induced by aldosterone was not one of the membrane proteins responsible for K secretion.

scholarly journals Role of the BK channel (KCa1.1) during activation of electrogenic K+ secretion in guinea pig distal colon

2012 ◽  
Vol 303 (12) ◽  
pp. G1322-G1334 ◽  
Author(s):  
Jin Zhang ◽  
Susan T. Halm ◽  
Dan R. Halm
Keyword(s):  
Guinea Pig ◽  
Apical Membrane ◽  
Splice Variants ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Distal Colon ◽  
Bk Channel ◽  
Prostaglandin E ◽  
Maximal Inhibition ◽  
K Secretion

Secretagogues acting at a variety of receptor types activate electrogenic K+ secretion in guinea pig distal colon, often accompanied by Cl− secretion. Distinct blockers of KCa1.1 (BK, Kcnma1), iberiotoxin (IbTx), and paxilline inhibited the negative short-circuit current ( Isc) associated with K+ secretion. Mucosal addition of IbTx inhibited epinephrine-activated Isc (epi Isc) and transepithelial conductance (epi Gt) consistent with K+ secretion occurring via apical membrane KCa1.1. The concentration dependence of IbTx inhibition of epi Isc yielded an IC50 of 193 nM, with a maximal inhibition of 51%. Similarly, IbTx inhibited epi Gt with an IC50 of 220 nM and maximal inhibition of 48%. Mucosally added paxilline (10 μM) inhibited epi Isc and epi Gt by ∼50%. IbTx and paxilline also inhibited Isc activated by mucosal ATP, supporting apical KCa1.1 as a requirement for this K+ secretagogue. Responses to IbTx and paxilline indicated that a component of K+ secretion occurred during activation of Cl− secretion by prostaglandin-E2 and cholinergic stimulation. Analysis of KCa1.1α mRNA expression in distal colonic epithelial cells indicated the presence of the ZERO splice variant and three splice variants for the COOH terminus. The presence of the regulatory β-subunits KCaβ1 and KCaβ4 also was demonstrated. Immunolocalization supported the presence of KCa1.1α in apical and basolateral membranes of surface and crypt cells. Together these results support a cellular mechanism for electrogenic K+ secretion involving apical membrane KCa1.1 during activation by several secretagogue types, but the observed K+ secretion likely required the activity of additional K+ channel types in the apical membrane.

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