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ATP-sensitive K + channels maintain resting membrane potential in interstitial cells of Cajal from the mouse colon. Eur J Pharmacol 2017; 809:98-104. [PMID: 28511870 DOI: 10.1016/j.ejphar.2017.05.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/12/2017] [Accepted: 05/12/2017] [Indexed: 11/20/2022]
Abstract
To investigate the role of ATP-sensitive K+(KATP) channels on pacemaker activity in interstitial cells of Cajal (ICC), whole-cell patch clamping, RT-PCR, and intracellular Ca2+([Ca2+]i) imaging were performed in cultured colonic ICC. Pinacidil (a K+ channel opener) hyperpolarized the membrane and inhibited the generation of pacemaker potential, and this effect was reversed by glibenclamide (a KATP channel blocker). RT-PCR showed that Kir 6.1 and SUR2B were expressed in Ano-1 positive colonic ICC. Glibenclamide depolarized the membrane and increased pacemaker potential frequency. However, 5-hydroxydecanoic acid (a mitochondrial KATP channel blocker) had no effects on pacemaker potentials. Phorbol 12-myristate 13-acetate (PMA; a protein kinase C activator) blocked the pinacidil-induced effects, and PMA alone depolarized the membrane and increased pacemaker potential frequency. Cell-permeable 8-bromo-cyclic AMP also increased pacemaker potential frequency. Recordings of spontaneous intracellular Ca2+([Ca2+]i) oscillations showed that glibenclamide increased the frequency of [Ca2+]i oscillations. In small intestinal ICC, glibenclamide alone did not alter the generation of pacemaker potentials, and Kir 6.2 and SUR2B were expressed in Ano-1 positive ICC. Therefore, KATP channels in colonic ICC are activated in resting state and play an important role in maintaining resting membrane potential.
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Wu MJ, Kee KH, Na J, Kim SW, Bae Y, Shin DH, Choi S, Jun JY, Jeong HS, Park JS. Pituitary Adenylate Cyclase-activating Polypeptide Inhibits Pacemaker Activity of Colonic Interstitial Cells of Cajal. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2015; 19:435-40. [PMID: 26330756 PMCID: PMC4553403 DOI: 10.4196/kjpp.2015.19.5.435] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 04/13/2015] [Accepted: 04/30/2015] [Indexed: 01/19/2023]
Abstract
This study aimed to investigate the effect of pituitary adenylate cyclase-activating peptide (PACAP) on the pacemaker activity of interstitial cells of Cajal (ICC) in mouse colon and to identify the underlying mechanisms of PACAP action. Spontaneous pacemaker activity of colonic ICC and the effects of PACAP were studied using electrophysiological recordings. Exogenously applied PACAP induced hyperpolarization of the cell membrane and inhibited pacemaker frequency in a dose-dependent manner (from 0.1 nM to 100 nM). To investigate cyclic AMP (cAMP) involvement in the effects of PACAP on ICC, SQ-22536 (an inhibitor of adenylate cyclase) and cell-permeable 8-bromo-cAMP were used. SQ-22536 decreased the frequency of pacemaker potentials, and cell-permeable 8-bromo-cAMP increased the frequency of pacemaker potentials. The effects of SQ-22536 on pacemaker potential frequency and membrane hyperpolarization were rescued by co-treatment with glibenclamide (an ATP-sensitive K(+) channel blocker). However, neither N (G)-nitro-L-arginine methyl ester (L-NAME, a competitive inhibitor of NO synthase) nor 1H-[1,2,4]oxadiazolo[4,3-α]quinoxalin-1-one (ODQ, an inhibitor of guanylate cyclase) had any effect on PACAP-induced activity. In conclusion, this study describes the effects of PACAP on ICC in the mouse colon. PACAP inhibited the pacemaker activity of ICC by acting through ATP-sensitive K(+) channels. These results provide evidence of a physiological role for PACAP in regulating gastrointestinal (GI) motility through the modulation of ICC activity.
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Affiliation(s)
- Mei Jin Wu
- Department of Physiology, Chonnam National University Medical School, Gwangju 501-757, Korea
| | - Keun Hong Kee
- Department of Pathology, College of Medicine, Chosun University, Gwangju 501-759, Korea
| | - Jisun Na
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju 501-759, Korea
| | - Seok Won Kim
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju 501-759, Korea
| | - Youin Bae
- Department of Dermatology, Hallym University Dongtan Sacred Heart Hospital, Hwaseong 445-907, Korea
| | - Dong Hoon Shin
- Department of Physiology, College of Medicine, Chosun University, Gwangju 501-759, Korea
| | - Seok Choi
- Department of Physiology, College of Medicine, Chosun University, Gwangju 501-759, Korea
| | - Jae Yeoul Jun
- Department of Physiology, College of Medicine, Chosun University, Gwangju 501-759, Korea
| | - Han-Seong Jeong
- Department of Physiology, Chonnam National University Medical School, Gwangju 501-757, Korea
| | - Jong-Seong Park
- Department of Physiology, Chonnam National University Medical School, Gwangju 501-757, Korea
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Lee S, Gim H, Shim JH, Jung Kim H, Lee JR, Kim SC, Kwon YK, Ha KT, So I, Kim BJ. The traditional herbal medicine, Ge-Gen-Tang, inhibits pacemaker potentials by nitric oxide/cGMP dependent ATP-sensitive K(+) channels in cultured interstitial cells of Cajal from mouse small intestine. JOURNAL OF ETHNOPHARMACOLOGY 2015; 170:201-209. [PMID: 26003723 DOI: 10.1016/j.jep.2015.05.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 04/06/2015] [Accepted: 05/12/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Ge-Gen-Tang (GGT) is a traditional Chinese medicinal formula composed of Puerariae radix (Pueraria lobata Ohwi), Ephedrae Herba (Ephedra sinica Stapf), Cinnamomi Ramulus (Cinnamomum cassia Blume), Paeoniae Radix (Paeonia lactiflora Pallas), Glycyrrhizae Radix preparata (Glycyrrhiza uralensis Fischer), Zingiberis Rhizoma (Zingiber officinale Roscoe), and Zizyphi Fructus (Ziziphus jujuba Mill. var. inermis Rehder) and is widely used to ameoliorate the symptoms of gastrointestinal (GI) disorders related to diarrhea and intestinal mucosal immunity and for anti-cold, antipyretic and analgesic in Eastern Asia. AIM OF THE STUDY Interstitial cells of Cajal (ICCs) are pacemaker cells in the GI tract that generate rhythmic oscillations in membrane potentials known as slow waves. We investigated the effects of GGT on pacemaker potentials in cultured ICCs from the mouse small intestine, and sought to identify the receptors and the action mechanisms involved. MATERIALS AND METHODS Enzymatic digestions were used to dissociate ICCs from mouse small intestine tissues. All experiments on ICCs were performed on within 12h after culture. A whole-cell patch-clamp configuration was used to record potentials (current clamp) from cultured ICCs. Intracellular Ca(2+) ([Ca(2+)]i) increase was studied in cultured ICCs using fura-2AM. All of the experiments were performed at 30-32°C. RESULTS Under the current clamping mode, GGT decreased the amplitude and frequency of pacemaker potentials; however, these effects were blocked by intracellular GDPβS, a G-protein inhibitor, and glibenclamide, a specific ATP-sensitive K(+) channels blocker. Prazosin (α1-adrenoceptor antagonist) and butoxamine (β2-adrenoceptor antagonist) did not block the GGT-induced effects, whereas atenolol (β1-adrenoceptor antagonist) blocked the GGT-induced effects. Also, yohimbine (α2-adrenoceptor antagonist) partially blocked the GGT-induced effects. Pretreatment with SQ-22536, an adenylate cyclase inhibitor, did not block the GGT-induced effects, whereas pretreatment with ODQ, a guanylate cyclase inhibitor, or L-NAME, an inhibitor of nitric oxide (NO) synthase, did. Additionally, [Ca(2+)]i analysis showed that GGT decreased [Ca(2+)]i. CONCLUSION These results suggest that GGT inhibits pacemaker potentials in ICCs in a G protein-, cGMP- and NO-dependent manner through stimulation of α2 and β1-adrenoceptors.
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MESH Headings
- Animals
- Cells, Cultured
- Cyclic GMP/metabolism
- Drugs, Chinese Herbal/pharmacology
- Female
- Interstitial Cells of Cajal/drug effects
- Interstitial Cells of Cajal/metabolism
- Intestine, Small/cytology
- Intestine, Small/drug effects
- Intestine, Small/metabolism
- KATP Channels/metabolism
- Male
- Membrane Potentials/drug effects
- Mice
- Mice, Inbred BALB C
- Nitric Oxide/metabolism
- Patch-Clamp Techniques
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/metabolism
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Affiliation(s)
- Soojin Lee
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea
| | - Huijin Gim
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea
| | - Ji Hwan Shim
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea
| | - Hyun Jung Kim
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea
| | - Jong Rok Lee
- Department of Pharmaceutical Engineering, Daegu Haany University, Gyeongsan 712-715, Republic of Korea
| | - Sang Chan Kim
- College of Oriental Medicine, Daegu Haany University, Gyeongsan 712-715, Republic of Korea
| | - Young Kyu Kwon
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea
| | - Ki-Tae Ha
- Division of Applied Medicine, School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea
| | - Insuk So
- Department of Physiology, College of Medicine, Seoul National University, Seoul 110-799, Republic of Korea
| | - Byung Joo Kim
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan 626-870, Republic of Korea.
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Lees-Green R, Du P, O'Grady G, Beyder A, Farrugia G, Pullan AJ. Biophysically based modeling of the interstitial cells of cajal: current status and future perspectives. Front Physiol 2011; 2:29. [PMID: 21772822 PMCID: PMC3131535 DOI: 10.3389/fphys.2011.00029] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 06/13/2011] [Indexed: 12/29/2022] Open
Abstract
Gastrointestinal motility research is progressing rapidly, leading to significant advances in the last 15 years in understanding the cellular mechanisms underlying motility, following the discovery of the central role played by the interstitial cells of Cajal (ICC). As experimental knowledge of ICC physiology has expanded, biophysically based modeling has become a valuable tool for integrating experimental data, for testing hypotheses on ICC pacemaker mechanisms, and for applications in in silico studies including in multiscale models. This review is focused on the cellular electrophysiology of ICC. Recent evidence from both experimental and modeling domains have called aspects of the existing pacemaker theories into question. Therefore, current experimental knowledge of ICC pacemaker mechanisms is examined in depth, and current theories of ICC pacemaking are evaluated and further developed. Existing biophysically based ICC models and their physiological foundations are then critiqued in light of the recent advances in experimental knowledge, and opportunities to improve these models are identified. The review concludes by examining several potential clinical applications of biophysically based ICC modeling from the subcellular through to the organ level, including ion channelopathies and ICC network degradation.
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Affiliation(s)
- Rachel Lees-Green
- Auckland Bioengineering Institute, The University of Auckland Auckland, New Zealand
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Choi S, Yeum CH, Kim YD, Park CG, Kim MY, Park JS, Jeong HS, Kim BJ, So I, Kim KW. Receptor tyrosine and MAP kinase are involved in effects of H(2)O(2) on interstitial cells of Cajal in murine intestine. J Cell Mol Med 2011; 14:257-66. [PMID: 20414970 PMCID: PMC3837618 DOI: 10.1111/j.1582-4934.2008.00403.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Hydrogen peroxide (H(2)O(2)) is involved in intestinal motility through changes of smooth muscle activity. However, there is no report as to the modulatory effects of H(2)O(2) on interstitial cells of Cajal (ICC). We investigated the H(2)O(2) effects and signal transductions to determine whether the intestinal motility can be modulated through ICC. We performed whole-cell patch clamp in cultured ICC from murine intestine and molecular analyses. H(2)O(2) hyperpolarized the membrane and inhibited pacemaker currents. These effects were inhibited by glibenclamide, an inhibitor of ATP-sensitive K+ (K(ATP)) channels. The free-radical scavenger catalase inhibited the H(2)O(2)-induced effects. MAFP and AACOCF3 (a cytosolic phospholipase A2 inhibitors) or SC-560 and NS-398 (a selective COX-1 and 2 inhibitor) or AH6809 (an EP2 receptor antagonist) inhibited the H(2)O(2)-induced effects. PD98059 (a mitogen activated/ERK-activating protein kinase inhibitor) inhibited the H(2)O(2)-induced effects, though SB-203580 (a p38 MAPK inhibitor) or a JNK inhibitor did not affect. H(2)O(2)-induced effects could not be inhibited by LY-294002 (an inhibitor of PI3-kinases), calphostin C (a protein kinase C inhibitor) or SQ-22536 (an adenylate cyclase inhibitor). Adenoviral infection analysis revealed H2O2 stimulated tyrosine kinase activity and AG 1478 (an antagonist of epidermal growth factor receptor tyrosine kinase) inhibited the H(2)O(2)-induced effects. These results suggest H(2)O(2) can modulate ICC pacemaker activity and this occur by the activation of K(ATP) channels through PGE(2) production via receptor tyrosine kinase-dependent MAP kinase activation.
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Affiliation(s)
- Seok Choi
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
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Kim BJ, Chae H, Kwon YK, Choi S, Jun JY, Jeon JH, So I, Kim SJ. Effects of imatinib mesylate in interstitial cells of Cajal from murine small intestine. Biol Pharm Bull 2011; 33:993-7. [PMID: 20522965 DOI: 10.1248/bpb.33.993] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The interstitial cells of Cajal (ICCs) are pacemakers in the gastrointestinal tract. The possibility of whether imatinib mesylate, a Kit receptor tyrosine kinase inhibitor, modulates pacemaker activities in the ICC was examined using the whole cell patch clamp technique. Imatinib decreased the amplitude of pacemaker potentials in a dose-dependent manner in current-clamp mode. Because the effects of imatinib on pacemaker potentials were the same as those of pinacidil, we examined the effect of glibenclamide on ICC exposed to imatinib. The effects of imatinib on pacemaker potentials were blocked by glibenclamide. To see whether the production of prostaglandins (PGs) is involved in the inhibitory effect of imatinib on pacemaker potentials, we tested the effects of naproxen (a non-selective cyclooxygenase inhibitor) and AH6809 (a prostaglandin EP1 and EP2 receptor antagonist). Naproxen and AH6809 blocked the inhibitory effects of imatinib on ICC. Butaprost (an EP2 receptor agonist) showed the actions on pacemaker potentials in the same manner as imatinib. However, SC 19220 (an EP1 receptor antagonist) has no effects. To investigate the involvement of cAMP and protein kinase A (PKA) in the effects of imatinib on ICC, SQ 22536 (an inhibitor of adenylate cyclase) and mPKAI (an inhibitor of myristoylated PKA) were used. Both SQ-22536 and mPKAI blocked the imatinib-mediated inhibition of pacemaker potentials. However, the protein kinase C (PKC) inhibitors did not block the imatinib-mediated inhibition of pacemaker potentials. These results indicate that imatinib inhibits the pacemaker potentials of ICC by activating ATP-sensitive K(+) channels and PKA-dependent, PKC-independent manner.
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Affiliation(s)
- Byung Joo Kim
- Division of Longevity and Biofunctional Medicine, Pusan National University School of Korean Medicine, Yangsan 626-870, Republic of Korea
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Bechmann LP, Best J, Haag S, Leineweber K, Gerken G, Holtmann G. Serotoninergic and non-serotoninergic effects of two tricyclic antidepressants on visceral nociception in a rat model. Scand J Gastroenterol 2009; 44:680-6. [PMID: 19396660 DOI: 10.1080/00365520902767272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Tricyclic antidepressants (TCAs) are well established in the treatment of patients with irritable bowel syndrome (IBS). The effects are believed to be linked to serotoninergic antinociceptive properties, but data on the antinociceptive effects of various TCAs with variable serotoninergic and non-serotoninergic properties have not been investigated. The aim of this study was to compare the antinociceptive effects of different TCAs. MATERIAL AND METHODS Colorectal distension (CRD) using a barostat device was carried out in rats and the visceromotor response (VMR) to CRD was quantified by abdominal wall electromyography. Prior to CRD, saline (control), amitriptyline (AM), desipramine (DES), reserpine (RES) or a combination of TCAs and RES (AM + RES or DES + RES) was applied intraperitoneally. Serum 5-HT levels were determined using high-performance liquid chromatography (HPLC). RES was used to antagonize the serotoninergic actions of TCAs in order to discriminate between these effects and others. RESULTS Both TCAs decreased the VMR compared to placebo. After RES application without TCAs, the VMR was increased compared to controls (6403 microV+/-1772 microV). Co-administration of AM and RES resulted in a modest decrease in VMR (5774 microV+/-1953 microV), while in rats treated with RES and DES the VMR again was significantly lower (3446 microV (+/-1347 microV; p <0.05)). 5-HT levels were higher in TCA pretreated rats than those in controls and significantly lower 5-HT levels were found in all rats pretreated with RES. CONCLUSIONS AM and DES have antinociceptive properties while RES is pro-nociceptive. The antinociceptive effects of DES are not abolished by RES pretreatment, while AM only attenuates the pro-nociceptive effects of RES. The non-serotoninergic properties of TCAs substantially contribute to the differences in the antinococeptive effects of various TCAs.
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Affiliation(s)
- Lars P Bechmann
- Department of Gastroenterology, University of Essen, Germany
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Zhu MH, Kim TW, Ro S, Yan W, Ward SM, Koh SD, Sanders KM. A Ca(2+)-activated Cl(-) conductance in interstitial cells of Cajal linked to slow wave currents and pacemaker activity. J Physiol 2009; 587:4905-18. [PMID: 19703958 DOI: 10.1113/jphysiol.2009.176206] [Citation(s) in RCA: 211] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Interstitial cells of Cajal (ICC) are unique cells that generate electrical pacemaker activity in gastrointestinal (GI) muscles. Many previous studies have attempted to characterize the conductances responsible for pacemaker current and slow waves in the GI tract, but the precise mechanism of electrical rhythmicity is still debated. We used a new transgenic mouse with a bright green fluorescent protein (copGFP) constitutively expressed in ICC to facilitate study of these cells in mixed cell dispersions. We found that ICC express a specialized 'slow wave' current. Reversal of tail current analysis showed this current was due to a Cl(-) selective conductance. ICC express ANO1, a Ca(2+)-activated Cl(-) channel. Slow wave currents are not voltage dependent, but a secondary voltage-dependent process underlies activation of these currents. Removal of extracellular Ca(2+), replacement of Ca(2+) with Ba(2+), or extracellular Ni(2+) (30 microm) blocked the slow wave current. Single Ca(2+)-activated Cl() channels with a unitary conductance of 7.8 pS were resolved in excised patches of ICC. These are similar in conductance to ANO1 channels (8 pS) expressed in HEK293 cells. Slow wave current was blocked in a concentration-dependent manner by niflumic acid (IC(50) = 4.8 microm). Slow wave currents are associated with transient depolarizations of ICC in current clamp, and these events were blocked by niflumic acid. These findings demonstrate a role for a Ca(2+)-activated Cl(-) conductance in slow wave current in ICC and are consistent with the idea that ANO1 participates in pacemaker activity.
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Affiliation(s)
- Mei Hong Zhu
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
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Zhu MH, Kim TW, Ro S, Yan W, Ward SM, Koh SD, Sanders KM. A Ca(2+)-activated Cl(-) conductance in interstitial cells of Cajal linked to slow wave currents and pacemaker activity. J Physiol 2009. [PMID: 19703958 DOI: 10.1113/jphysiol.2009.176206.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Interstitial cells of Cajal (ICC) are unique cells that generate electrical pacemaker activity in gastrointestinal (GI) muscles. Many previous studies have attempted to characterize the conductances responsible for pacemaker current and slow waves in the GI tract, but the precise mechanism of electrical rhythmicity is still debated. We used a new transgenic mouse with a bright green fluorescent protein (copGFP) constitutively expressed in ICC to facilitate study of these cells in mixed cell dispersions. We found that ICC express a specialized 'slow wave' current. Reversal of tail current analysis showed this current was due to a Cl(-) selective conductance. ICC express ANO1, a Ca(2+)-activated Cl(-) channel. Slow wave currents are not voltage dependent, but a secondary voltage-dependent process underlies activation of these currents. Removal of extracellular Ca(2+), replacement of Ca(2+) with Ba(2+), or extracellular Ni(2+) (30 microm) blocked the slow wave current. Single Ca(2+)-activated Cl() channels with a unitary conductance of 7.8 pS were resolved in excised patches of ICC. These are similar in conductance to ANO1 channels (8 pS) expressed in HEK293 cells. Slow wave current was blocked in a concentration-dependent manner by niflumic acid (IC(50) = 4.8 microm). Slow wave currents are associated with transient depolarizations of ICC in current clamp, and these events were blocked by niflumic acid. These findings demonstrate a role for a Ca(2+)-activated Cl(-) conductance in slow wave current in ICC and are consistent with the idea that ANO1 participates in pacemaker activity.
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Affiliation(s)
- Mei Hong Zhu
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
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10
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Abdul-Baki H, El Hajj II, ElZahabi L, Azar C, Aoun E, Skoury A, Chaar H, Sharara AI. A randomized controlled trial of imipramine in patients with irritable bowel syndrome. World J Gastroenterol 2009; 15:3636-42. [PMID: 19653341 PMCID: PMC2721237 DOI: 10.3748/wjg.15.3636] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the efficacy of low-dose imipramine in relieving symptoms associated with the irritable bowel syndrome (IBS).
METHODS: A randomized, double-blind trial of 25 mg imipramine vs matched placebo for 12 wk was performed. Doubling the dose was allowed once at week 2 in case of an unsatisfactory early response. Primary efficacy variables were subjective global symptom relief and quality of life (QoL) using SF-36 at week 12.
RESULTS: One hundred and seven patients were enrolled by advertisement or referral by general practitioners and 56 (31 imipramine: 25 placebo) completed the 16-wk study. Baseline characteristics were comparable. A high overall dropout rate was noted in the imipramine and placebo arms (47.5% vs 47.9%, P > 0.05), a mean of 25.0 and 37.4 d from enrollment, respectively (P < 0.05). At the end of 12 wk, there was a significant difference in global symptom relief with imipramine over placebo (per-protocol: 80.6% vs 48.0%, P = 0.01) and a trend on intent-to-treat (ITT) analysis (42.4% vs 25.0%, P = 0.06). This improvement was evident early and persisted to week 16 (P = 0.024 and 0.053 by per-protocol and ITT analyses, respectively). Mean cumulative and component-specific SF-36 scores improved in the imipramine group only (per-protocol, P < 0.01). Drug-related adverse events leading to patient dropout were more common in the imipramine group (25.4% vs 12.5%, P > 0.05).
CONCLUSION: Imipramine may be effective in the treatment of IBS patients and is associated with improved QoL. Careful patient selection, initiation of a low dose with gradual escalation and monitoring for side effects may result in an improved therapeutic response.
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Bouras EP, Talley NJ, Camilleri M, Burton DD, Heckman MG, Crook JE, Richelson E. Effects of amitriptyline on gastric sensorimotor function and postprandial symptoms in healthy individuals: a randomized, double-blind, placebo-controlled trial. Am J Gastroenterol 2008; 103:2043-50. [PMID: 18803000 PMCID: PMC3897125 DOI: 10.1111/j.1572-0241.2008.02021.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Low-dose tricyclic antidepressants have been used to treat chronic somatic and gastrointestinal pain disorders, including refractory functional dyspepsia. However, there are only limited data on the effects of these drugs on upper gastrointestinal function. AIM To compare the effects of two doses of amitriptyline (AMT) and placebo on gastric accommodation, emptying, satiation, and postprandial symptoms in healthy volunteers. METHODS Using a parallel-group, double-blind, placebo-controlled design, 41 healthy volunteers were randomized to AMT 25 mg, AMT 50 mg, or placebo for 2 wk. During the final 3 days of therapy, the following end points were assessed: fasting and postprandial gastric volumes, 2- and 4-h gastric emptying, time and volume to maximum satiation using a nutrient drink test, and postprandial symptoms 30 min later using 10-cm visual analog scales. AMT and metabolite levels were measured. RESULTS AMT slowed gastric emptying at 2 h (median 75% for placebo, 57% for AMT 25 mg, 67% for AMT 50 mg; P= 0.037) and 4 h (median 98% for placebo, 96% for AMT 25 mg, 92% for AMT 50 mg; P= 0.003). AMT did not affect gastric volumes or satiation volume, but it did reduce nausea scores at 30 min in a dose-dependent manner (median 2.1 for placebo, 0.9 for AMT 25 mg, and 0.0 for AMT 50 mg; P= 0.009). CONCLUSION In healthy volunteers, AMT slows gastric emptying of solids, but it does not significantly affect gastric volumes or satiation. AMT reduces nausea after challenge with a high calorie liquid load.
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Affiliation(s)
- Ernest P Bouras
- Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida 32211, USA
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