scholarly journals Quercetin Inhibits Pacemaker Potentials via Nitric Oxide/cGMP-Dependent Activation and TRPM7/ANO1 Channels in Cultured Interstitial Cells of Cajal from Mouse Small Intestine

2015 ◽  
Vol 35 (6) ◽  
pp. 2422-2436 ◽  
Author(s):  
Huijin Gim ◽  
Joo Hyun Nam ◽  
Soojin Lee ◽  
Ji Hwan Shim ◽  
Hyun Jung Kim ◽  
...  
Keyword(s):  
Small Intestine ◽  
Opioid Receptor ◽  
Interstitial Cells Of Cajal ◽  
Pacemaker Activity ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Pacemaker Potentials ◽  
Cells Of Cajal ◽  
Gi Motility

Background: Quercetin regulates gastrointestinal (GI) motor activity but the molecular mechanism involved has not been determined. The authors investigated the effects of quercetin, a flavonoid present in various foods, on the pacemaker activities of interstitial cells of Cajal (ICCs) in murine small intestine in vitro and on GI motility in vivo. Materials and Methods: Enzymatic digestion was used to dissociate ICCs from mouse small intestines. The whole-cell patch-clamp configuration was used to record pacemaker potentials in cultured ICCs in the absence or presence of quercetin and to record membrane currents of transient receptor potential melastatin (TRPM) 7 or transmembrane protein 16A (Tmem16A, anoctamin1 (ANO1)) overexpressed in human embryonic kidney (HEK) 293 cells. The in vivo effects of quercetin on GI motility were investigated by measuring the intestinal transit rates (ITRs) of Evans blue in normal mice. Results: Quercetin (100-200 μM) decreased the amplitudes and frequencies of pacemaker activity in a concentration-dependent manner in current clamp mode, but this action was blocked by naloxone (a pan-opioid receptor antagonist) and by GDPβS (a GTP-binding protein inhibitor). However, potassium channels were not involved in these inhibitory effects of quercetin. To study the quercetin signaling pathway, we examined the effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of guanylate cyclase, and of RP-8-CPT-cGMPS, an inhibitor of protein kinase G (PKG). These inhibitors blocked the inhibitory effects of quercetin on pacemaker activities. Also, L-NAME (100 μM), a non-selective NO synthase (NOS) inhibitor, blocked the effects of quercetin on pacemaker activity and quercetin stimulated cGMP production. Furthermore, quercetin inhibited both Ca2+-activated Cl- channels (TMEM16A, ANO1) and TRPM7 channels. In vivo, quercetin (10-100 mg/kg, p.o.) decreased ITRs in normal mice in a dose-dependent manner. Conclusions: Quercetin inhibited ICC pacemaker activities by inhibiting TRPM7 and ANO1 via opioid receptor signaling pathways in cultured murine ICCs. The study shows quercetin attenuates GI tract motility, and suggests quercetin be considered the basis for the development of novel spasmolytic agents for the prevention or alleviation of GI motility dysfunctions.

scholarly journals Magnolia Officinalis Bark Extract Induces Depolarization of Pacemaker Potentials Through M2 and M3 Muscarinic Receptors in Cultured Murine Small Intestine Interstitial Cells of Cajal

2017 ◽  
Vol 43 (5) ◽  
pp. 1790-1802 ◽  
Author(s):  
Hyun Jung Kim ◽  
Taewon Han ◽  
Yun Tai Kim ◽  
Insuk So ◽  
Byung Joo Kim
Keyword(s):  
Receptor Antagonist ◽  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
Pacemaker Potential ◽  
Pacemaker Potentials ◽  
Magnolia Officinalis ◽  
Cells Of Cajal ◽  
Gi Motility

Background: Magnolia officinalis Rehder and EH Wilson (M. officinalis) are traditional Chinese medicines widely used for gastrointestinal (GI) tract motility disorder in Asian countries. We investigated the effects of an ethanol extract of M. officinalis (MOE) on the pacemaker potentials of cultured interstitial cells of Cajal (ICCs) in vitro and its effects on GI motor functions in vivo. Methods: We isolated ICCs from small intestines, and the whole-cell patch-clamp configuration was used to record the pacemaker potentials in cultured ICCs in vitro. Both gastric emptying (GE) and intestinal transit rates (ITRs) were investigated in normal and GI motility dysfunction (GMD) mice models in vivo. Results: MOE depolarized ICC pacemaker potentials dose-dependently. Pretreatment with methoctramine (a muscarinic M2 receptor antagonist) and 4-DAMP (a muscarinic M3 receptor antagonist) inhibited the effects of MOE on the pacemaker potential relative to treatment with MOE alone. In addition, MOE depolarized pacemaker potentials after pretreatment with Y25130 (a 5-HT3 receptor antagonist), GR113808 (a 5-HT4 receptor antagonist) or SB269970 (a 5-HT7 receptor antagonist). However, pretreatment with RS39604 (a 5-HT4 receptor antagonist) blocked MOE-induced pacemaker potential depolarizations. Intracellular GDPβS inhibited MOE-induced pacemaker potential depolarization, as did pretreatment with Ca2+ free solution or thapsigargin. In normal mice, the GE and ITR values were significantly and dose-dependently increased by MOE. In loperamide-and cisplatin-induced GE delay models, MOE administration reversed the GE deficits. The ITRs of the GMD mice were significantly reduced relative to those of normal mice, which were significantly and dose-dependently reversed by MOE. Conclusion: These results suggest that MOE dose-dependently depolarizes ICCs pacemaker potentials through M2 and M3 receptors via internal and external Ca2+ regulation through G protein pathways in vitro. Moreover, MOE increased GE and ITRs in vivo in normal and GMD mouse models. Taken together, the results of this study show that MOE have the potential for development as a gastroprokinetic agent in GI motility function.

scholarly journals Menthol Modulates Pacemaker Potentials through TRPA1 Channels in Cultured Interstitial Cells of Cajal from Murine Small Intestine

2016 ◽  
Vol 38 (5) ◽  
pp. 1869-1882 ◽  
Author(s):  
Hyun Jung Kim ◽  
Jinhong Wie ◽  
Insuk So ◽  
Myeong Ho Jung ◽  
Ki-Tae Ha ◽  
...  
Keyword(s):  
Small Intestine ◽  
Membrane Potential ◽  
Interstitial Cells Of Cajal ◽  
Rho Kinase ◽  
Thromboxane A2 ◽  
Interstitial Cells ◽  
Dependent Manner ◽  
Induced Membrane ◽  
Pacemaker Potentials ◽  
Cells Of Cajal

Background/Aims: ICCs are the pacemaker cells responsible for slow waves in gastrointestinal (GI) smooth muscle, and generate periodic pacemaker potentials in current-clamp mode. Methods: The effects of menthol on the pacemaker potentials of cultured interstitial cells of Cajal (ICCs) from mouse small intestine were studied using the whole cell patch clamp technique. Results: Menthol (1 - 10 μM) was found to induce membrane potential depolarization in a concentration-dependent manner. The effects of various TRP channel antagonists were examined to investigate the receptors involved. The addition of the TRPM8 antagonist, AMTB, did not block menthol-induced membrane potential depolarizations, but TRPA1 antagonists (A967079 or HC-030031) blocked the effects of menthol, as did intracellular GDPβS. Furthermore, external and internal Ca2+ levels were found to depolarize menthol-induced membrane potentials, whereas external Na+ was not. Y-27632 (a Rho kinase inhibitor), SC-560 (a selective COX 1 inhibitor), NS-398 (a selective COX 2 inhibitor), ozagrel (a thromboxane A2 synthase inhibitor) and SQ-29548 (highly selective thromboxane receptor antagonist) were used to investigate the involvements of Rho-kinase, cyclooxygenase (COX), and the thromboxane pathway in menthol-induced membrane potential depolarizations, and all inhibitors were found to block the effect of menthol. Conclusions: These results suggest that menthol-induced membrane potential depolarizations occur in a G-protein-, Ca2+-, Rho-kinase-, COX-, and thromboxane A2-dependent manner via TRPA1 receptor in cultured ICCs in murine small intestine. The study shows ICCs are targeted by menthol and that this interaction can affect intestinal motility.

Pacemaker potentials generated by interstitial cells of Cajal in the murine intestine

2005 ◽  
Vol 288 (3) ◽  
pp. C710-C720 ◽  
Author(s):  
Yoshihiko Kito ◽  
Sean M. Ward ◽  
Kenton M. Sanders
Keyword(s):  
Interstitial Cells Of Cajal ◽  
Circular Muscle ◽  
Muscle Cells ◽  
Interstitial Cells ◽  
Slow Waves ◽  
Pacemaker Activity ◽  
Dependent Manner ◽  
Plateau Potential ◽  
Pacemaker Potentials ◽  
Cells Of Cajal

Pacemaker potentials were recorded in situ from myenteric interstitial cells of Cajal (ICC-MY) in the murine small intestine. The nature of the two components of pacemaker potentials (upstroke and plateau) were investigated and compared with slow waves recorded from circular muscle cells. Pacemaker potentials and slow waves were not blocked by nifedipine (3 μM). In the presence of nifedipine, mibefradil, a voltage-dependent Ca2+ channel blocker, reduced the amplitude, frequency, and rate of rise of upstroke depolarization (d V/d tmax) of pacemaker potentials and slow waves in a dose-dependent manner (1–30 μM). Mibefradil (30 μM) changed the pattern of pacemaker potentials from rapidly rising, high-frequency events to slowly depolarizing, low-frequency events with considerable membrane noise (unitary potentials) between pacemaker potentials. Caffeine (3 mM) abolished pacemaker potentials in the presence of mibefradil. Pinacidil (10 μM), an ATP-sensitive K+ channel opener, hyperpolarized ICC-MY and increased the amplitude and d V/d tmax without affecting frequency. Pinacidil hyperpolarized smooth muscle cells and attenuated the amplitude and d V/d tmax of slow waves without affecting frequency. The effects of pinacidil were blocked by glibenclamide (10 μM). These data suggest that slow waves are electrotonic potentials driven by pacemaker potentials. The upstroke component of pacemaker potentials is due to activation of dihydropyridine-resistant Ca2+ channels, and this depolarization entrains pacemaker activity to create the plateau potential. The plateau potential may be due to summation of unitary potentials generated by individual or small groups of pacemaker units in ICC-MY. Entrainment of unitary potentials appears to depend on Ca2+ entry during upstroke depolarization.

A mathematical model of pacemaker activity recorded from mouse small intestine

2006 ◽  
Vol 364 (1842) ◽  
pp. 1135-1154 ◽  
Author(s):  
Jae Boum Youm ◽  
Nari Kim ◽  
Jin Han ◽  
Euiyong Kim ◽  
Hyun Joo ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Small Intestine ◽  
Action Potentials ◽  
Interstitial Cells Of Cajal ◽  
Animal Experiments ◽  
Pacemaker Activity ◽  
Mouse Small Intestine ◽  
Pacemaker Potentials ◽  
Cyclic Changes ◽  
Cells Of Cajal

The pacemaker activity of interstitial cells of Cajal (ICCs) has been known to initiate the propagation of slow waves along the whole gastrointestinal tract through spontaneous and repetitive generation of action potentials. We studied the mechanism of the pacemaker activity of ICCs in the mouse small intestine and tested it using a mathematical model. The model includes ion channels, exchanger, pumps and intracellular machinery for Ca 2+ regulation. The model also incorporates inositol 1,4,5-triphosphate (IP 3 ) production and IP 3 -mediated Ca 2+ release activities. Most of the parameters were obtained from the literature and were modified to fit the experimental results of ICCs from mouse small intestine. We were then able to compose a mathematical model that simulates the pacemaker activity of ICCs. The model generates pacemaker potentials regularly and repetitively as long as the simulation continues. The frequency was set at 20 min −1 and the duration at 50% repolarization was 639 ms. The resting and overshoot potentials were −78 and +1.2 mV, respectively. The reconstructed pacemaker potentials closely matched those obtained from animal experiments. The model supports the idea that cyclic changes in [Ca 2+ ] i and [IP 3 ] play key roles in the generation of ICC pacemaker activity in the mouse small intestine.

Depolarization of pacemaker potentials by caffeic acid phenethyl ester in interstitial cells of Cajal from the murine small intestine

2020 ◽  
Vol 98 (4) ◽  
pp. 201-210 ◽  
Author(s):  
Jeong Nam Kim ◽  
Byung Joo Kim
Keyword(s):  
Small Intestine ◽  
Caffeic Acid ◽  
Interstitial Cells Of Cajal ◽  
Caffeic Acid Phenethyl Ester ◽  
Pi3 Kinase ◽  
Dependent Manner ◽  
Pacemaker Potential ◽  
Pacemaker Potentials ◽  
Murine Small Intestine ◽  
Cells Of Cajal

Interstitial cells of Cajal (ICCs) are pacemaker cells in the gastrointestinal (GI) tract and generate pacemaker potentials. In this study, we investigated the effects of caffeic acid phenethyl ester (CAPE) on the pacemaker potentials of ICCs from the mouse small or large intestine. Using the whole-cell patch-clamp configuration, we found that CAPE depolarized the pacemaker potentials of cultured ICCs from the murine small intestine in a dose-dependent manner. The estrogen receptor (ER) β antagonist PHTPP completely inhibited CAPE-induced depolarization, but the ERα antagonist BHPI did not. Intracellular GDP-β-S and pretreatment with Ca2+-free solution or thapsigargin also blocked CAPE-induced depolarization. To investigate the mechanisms of CAPE-mediated depolarization of ICCs, we used the nonselective cation channel (NSCC) inhibitor flufenamic acid, the Cl– channel blocker, mitogen-activated protein kinase (MAPK) inhibitors PD98059, SB203580, or SP600125, and PI3 kinase inhibitor LY294002. All inhibitors blocked the CAPE-induced pacemaker potential depolarization of ICCs. These results suggest that CAPE induces pacemaker potential depolarization through ERβ in a G protein, NSCC, Cl– channel, MAPK- and PI3 kinase dependent manner via intracellular and extracellular Ca2+ regulation in the murine small intestine. CAPE may therefore modulate GI motility by acting on ICCs in the murine small intestine.

scholarly journals Involvement of MAPKs and PLC Pathways in Modulation of Pacemaking Activity by So-Cheong-Ryong-Tang in Interstitial Cells of Cajal from Murine Small Intestine

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Min Woo Hwang ◽  
Hee Jung Lee ◽  
Ho Joon Song ◽  
Byung Joo Kim
Keyword(s):  
Small Intestine ◽  
Receptor Antagonist ◽  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
Pacemaker Activity ◽  
Pipette Solution ◽  
Current Clamp Mode ◽  
Pacemaker Potentials ◽  
Cells Of Cajal ◽  
Mapk Inhibitor

Purpose. Interstitial cells of Cajal (ICCs) are the pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. We have aimed to investigate the effects of Socheongryong-Tang (SCRT) in ICCs from mouse’s small intestine.Methods. The whole-cell patch-clamp configuration was used to record membrane potentials from cultured ICCs. Intracellular Ca2+([Ca2+]i) increase was studied in cultured ICCs using fura-2 AM.Results. ICCs generated pacemaker potentials in mouse’s small intestine. SCRT produced membrane depolarization in current clamp mode. Y25130 (5-HT3receptor antagonist) and RS39604 (5-HT4receptor antagonist) blocked SCRT-induced membrane depolarizations, whereas SB269970 (5-HT7receptor antagonist) did not. When GDP-β-S (1 mM) was in the pipette solution, SCRT did not induce the membrane depolarizations.[Ca2+]ianalysis showed that SCRT increased[Ca2+]i. In the presence of PD98059 (p42/44 MAPK inhibitor), SCRT did not produce membrane depolarizations. In addition, SB203580 (p38 MAPK inhibitor) and JNK inhibitors blocked the depolarizations by SCRT in pacemaker potentials. Furthermore, the membrane depolarizations by SCRT were not inhibited by U-73122, an active phospholipase C (PLC) inhibitor, but by U-73343, an inactive PLC inhibitor.Conclusion. These results suggest that SCRT might affect GI motility by the modulation of pacemaker activity through MAPKs and PLC pathways in the ICCs.

scholarly journals Effects of ATP on Pacemaker Activity of Interstitial Cells of Cajal from the Mouse Small Intestine

2018 ◽  
Vol 54 (1) ◽  
pp. 63
Author(s):  
Il Koo Park ◽  
Jin Ho Kim ◽  
Chan Guk Park ◽  
Man Yoo Kim ◽  
Shankar Prasad Parajuli ◽  
...  
Keyword(s):  
Small Intestine ◽  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
Pacemaker Activity ◽  
Mouse Small Intestine ◽  
Cells Of Cajal
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