Cajal Of Murine Small Intestine Research Articles

Effects of black garlic on the pacemaker potentials of interstitial cells of Cajal in murine small intestine in vitro and on gastrointestinal motility in vivo

ABSTRACT Black garlic (BG) is a newly explored food stuff obtained via fermentation of raw, healthy garlic, especially in Asian countries. Interstitial cells of Cajal (ICC) are the pacemaker cells of gastrointestinal (GI) motility. The purpose of this study was to investigate the effects of BG extract on the pacemaker potentials of the ICC in the small intestines of mice and the possibility of controlling GI motility. The antioxidant activity of BG extract was also investigated. The whole-cell electrophysiological method was used to measure pacemaker potentials of the ICC in vitro, whereas GI motility was measured using the intestinal transit rate (ITR) in vivo. BG extract depolarized the pacemaker potentials of the ICC. Y25130 and RS39604 5-HT receptor antagonists could not inhibit the effect of BG extract on the pacemaker potentials of the ICC, whereas the 5-HT receptor antagonist SB269970 could. Pre-treatment with external Na+ (5 mM) or Ca2+-free solution inhibited the BG extract-induced depolarization of the ICC. With SB203580, PD98059, or c-jun NH2-terminal kinase II inhibitor pre-treatment, BG extract did not induce pacemaker potential depolarization. Moreover, the ITR values were increased by BG extract. Elevation of the ITR due to BG extract was related with increased protein expression of the 5-HT7 receptors. In addition, BG extract showed antioxidant activity. Collectively, these results highlight the ability of BG extract to regulate GI motility and the possibility of using it to develop GI motility modulators in the future. Moreover, BG showed immense potential as an antioxidant.

Modulation of Fermented Lotus Root on Pacemaker Potentials in Interstitial Cells of Cajal of Murine Small Intestine

Modulation of Fermented Lotus Root on Pacemaker Potentials in Interstitial Cells of Cajal of Murine Small Intestine

Mirtazapine Regulates Pacemaker Potentials of Interstitial Cells of Cajal in Murine Small Intestine

Mirtazapine Regulates Pacemaker Potentials of Interstitial Cells of Cajal in Murine Small Intestine

C-Kit-stem cell factor signal-independent development of interstitial cells of Cajal in murine small intestine.

c-Kit receptor tyrosine kinase and its ligand stem cell factor (SCF) play critical roles in regulating the development and proliferation of various cells, including the interstitial cells of Cajal (ICC) in the gastrointestinal tract. Many subtypes of ICC are known to be lacking in c-Kit-SCF-insufficient mice, such as W/Wv and Sl/Sld, whereas ICC-deep muscular plexus (DMP) in small intestine are not lacking. In this study, we examine ICC-DMP development in normal and c-Kit-SCF signal-insufficient mice. In normal mice, numerous ICC-DMP labeled with c-Kit and neurokinin 1 receptor (NK1R) antibodies were observed only in the duodenum on the day of birth, in the duodenum and the jejunum on postnatal day 4 and throughout the small intestine after postnatal day 6. In W mutant mice (W/Wv, Wv/Wv, W/W), ICC-DMP investigated using c-Kit and NK1R immunoreactivities were similar to that in normal mice. c-Kit ligand SCF-deficient mice (Sl/Sl) also showed almost identical ICC-DMP development and proliferation as normal mice. These results show that the development and proliferation of ICC-DMP occur in the postnatal period independent of c-Kit-SCF signaling.

Effects of Olanzapine on the Pacemaker Potentials of Interstitial Cells of Cajal in Murine Small Intestine

Effects of Olanzapine on the Pacemaker Potentials of Interstitial Cells of Cajal in Murine Small Intestine

Effects of Prunus mume Siebold & Zucc. in the pacemaking activity of interstitial cells of Cajal in murine small intestine.

Interstitial cells of Cajal (ICCs) function as pacemaker cells in the gastrointestinal (GI) tract and therefore, serve an important role in regulating GI motility. The effects of a species of plum (Prunus mume Siebold & Zucc.) on cultured ICC cluster-induced pacemaker potentials in the mouse small intestine were investigated, and the effects of a methanolic extract of Prunus mume (m-PM) on ICC pacemaker activities were examined using the whole-cell patch-clamp technique. ICC pacemaker membrane potentials were depolarized by m-PM in a concentration dependent manner in current clamp mode. 4-Diphenylacetoxy-N-methyl-piperidine methiodide, which is a muscarinic 3 (M3) receptor antagonist, was able to block m-PM-induced pacemaker potential increases, whereas methoctramine, which is a muscarinic 2 (M2) receptor antagonist, was not. When 1 mM guanosine diphosphate β-5 was present in the pipette solution, m-PM induced slight pacemaker depolarization. Following pretreatment in bath solution of Ca2+-free solution or a Ca2+-ATPase inhibitor in endoplasmic reticulum, the pacemaker currents were inhibited. Furthermore, pretreatment with PD98059, SB203580 or SP600125, which is a c-jun NH2-terminal kinase inhibitor, blocked m-PM-induced ICC potential depolarization. Furthermore, m-PM inhibited transient receptor potential melastatin (TRPM) 7 channels, but did not affect Ca2+-activated Cl- channels. These results suggest that m-PM is able to modulate pacemaker potentials through the muscarinic M3 receptor, via G-protein and external and internal Ca2+, in a mitogen-activated protein kinase and TRPM7-dependent manner. Therefore, m-PM may provide a basis for the development of a novel gastroprokinetic agent.

Effects of Prunus Mume Siebold & Zucc. On the Pacemaking Activities of Interstitial Cells of Cajal in Murine Small Intestine

Interstitial cells of Cajal (ICCs) are the pacemaker cells in the gastrointestinal (GI) tract and play an important role in the regulation of GI motility. The authors investigated the effects of a plum (Prunus mume Siebold & Zucc.) on the pacemaker potentials of cultured ICCs from mouse small intestine. The effects of a methanolic extract of Prunus mume (m-PM) on ICC pacemaking activities were examined using the whole-cell patch clamp technique. ICC pacemaker membrane potentials were depolarized by m-PM in a concentration dependent manner in current clamp mode. 4-DAMP (a muscarinic M3 receptor antagonist) blocked m-PM-induced pacemaker depolarizations, whereas methoctramine (a muscarinic M2 receptor antagonist) did not. When GDP-β-S (1 mM) was in the pipette solution, m-PM induced slight pacemaker depolarization. Pretreatment with Ca2+-free solution or thapsigargin (a Ca2+-ATPase inhibitor in endoplasmic reticulum) abolished the generation of pacemaker currents and suppressed m-PM-induced pacemaker membrane depolarization. Also, pretreatments with PD98059, SB203580, or JNK II inhibitor blocked m-PM-induced ICC depolarizations. Furthermore, m-PM inhibited transient receptor potential melastatin (TRPM) 7 channels, but did not affect Ca2+-activated Cl- channels. These results suggest that m-PM modulates pacemaker potentials through muscarinic M3 receptor via G-protein and external and internal Ca2+ in a mitogen-activated protein kinase and TRPM7 dependent manner. In addition, they also indicate that the methanoic extract of Prunus mume Siebold and Zucc. offers an excellent basis for the development of a novel gastroprokinetic agent.

Inhibitory Effects of Naeso-san on Pacemaker Potentials in Interstitial Cells of Cajal of Murine Small Intestine

The purpose of this study was to investigate the effects of Naeso-san in interstitial cells of Cajal (ICCs) in murine small intestine. First, we isolated ICCs from murine small intestine. After that, we cultured these cells for 1 days. The patch-clamp technique was applied on ICCs that formed network-like structures in culture (1 days). Spontaneous rhythms were routinely recorded from cultured ICCs under current-clamp conditions, and the ICCs within networks displayed more robust electrical rhythms (pacemaker potentials). To understand the relationship between Naeso-san and pacemaker activity in ICCs, we examined the effects of Naeso-san on pacemaker potentials of ICCs. In current clamp mode (I = 0), the addition of Naeso-san (10 mg/ml ? 50 mg/ml) decreased the amplitude and frequency of the pacemaker potentials of ICCs in a dose dependent manner. However, these effects were blocked by intracellular GDPβ S, a G-protein inhibitor, and glibenclamide, a specific ATP-sensitive K+ channels blocker. Pretreatment with SQ-22536, an adenylate cyclase inhibitor, did not block the Naeso-san induced effects, whereas pretreatment with ODQ, a guanylate cyclase inhibitor, or L-NAME, an inhibitor of nitric oxide (NO) synthase blocked the Naeso-san induced effects. Our findings provide insight into unraveling the modulation of Naeso-san in pacemaker potentials of ICCs and developing therapeutic agents against gastrointestinal motility disorders.

Effects of Samchulkunbi-tang in Cultured Interstitial Cells of Cajal of Murine Small Intestine

We studied the modulation of pacemaker activities by Samchulkunbi-tang (SCKB) in cultured interstitial cells of Cajal (ICC) from murine small intestine with the whole-cell patch-clamp technique. Externally applied SCKB produced membrane depolarization in the current-clamp mode. The pretreatment with Ca 2+ -free solution and thapsigargin, a Ca 2+ -ATPase inhibitor in endoplasmic reticulum, abolished the generation of pacemaker potentials and suppressed the SCKB-induced action. The application of flufenamic acid (a nonselective cation channel blocker) abolished the generation of pacemaker potentials by SCKB. However, the application of niflumic acid (a chloride channel blocker) did not inhibit the generation of pacemaker potentials by SCKB. In addition, the membrane depolarizations were inhibited by not only GDP-β-S, which permanently binds G-binding proteins, but also U-73122, an active phospholipase C inhibitor. These results suggest that SCKB modulates the pacemaker activities by nonselective cation channels and external Ca 2+ influx and internal Ca 2+ release via G-protein and phospholipase C-dependent mechanism. Therefore, the ICC are targets for SCKB and their interaction can affect intestinal motility.

Effects of Histamine on Cultured Interstitial Cells of Cajal in Murine Small Intestine

Interstitial cells of Cajal (ICCs) are the pacemaker cells in the gastrointestinal tract, and histamine is known to regulate neuronal activity, control vascular tone, alter endothelial permeability, and modulate gastric acid secretion. However, the action mechanisms of histamine in mouse small intestinal ICCs have not been previously investigated, and thus, in the present study, we investigated the effects of histamine on mouse small intestinal ICCs, and sought to identify the receptors involved. Enzymatic digestions were used to dissociate ICCs from small intestines, and the whole-cell patch-clamp configuration was used to record potentials (in current clamp mode) from cultured ICCs. Histamine was found to depolarize resting membrane potentials concentration dependently, and whereas 2-PEA (a selective H1 receptor agonist) induced membrane depolarizations, Dimaprit (a selective H2-agonist), R-alpha-methylhistamine (R-alpha-MeHa; a selective H3-agonist), and 4-methylhistamine (4-MH; a selective H4-agonist) did not. Pretreatment with Ca2+-free solution or thapsigargin (a Ca2+-ATPase inhibitor in endoplasmic reticulum) abolished the generation of pacemaker potentials and suppressed histamine-induced membrane depolarization. Furthermore, treatments with U-73122 (a phospholipase C inhibitor) or 5-fluoro-2-indolyl des-chlorohalopemide (FIPI; a phospholipase D inhibitor) blocked histamine-induced membrane depolarizations in ICCs. On the other hand, KT5720 (a protein kinase A inhibitor) did not block histamine-induced membrane depolarization. These results suggest that histamine modulates pacemaker potentials through H1 receptor-mediated pathways via external Ca2+ influx and Ca2+ release from internal stores in a PLC and PLD dependent manner.

Differential gene expression in functional classes of interstitial cells of Cajal in murine small intestine

Interstitial cells of Cajal (ICC) have important functions in regulation of motor activity in the gastrointestinal tract. In murine small intestine, ICC are gathered in the regions of the myenteric plexus (ICC-MY) and the deep muscular plexus (ICC-DMP). These two classes of ICC have different physiological functions. ICC-MY are pacemaker cells and generate the slow-wave electrical rhythmicity of gastrointestinal organs. ICC-DMP form synaptic connections with the varicose nerve terminals of enteric motor neurons and are involved in reception and transduction of motor neurotransmission. Gene expression underlying specific functions of ICC classes is incompletely understood. In the present study, we used recently developed highly selective techniques to isolate the two functional ICC classes from enzymatically dispersed intestinal muscles by fluorescence-activated cell sorting. The transcriptomes of ICC-MY and ICC-DMP were investigated using oligonucleotide microarray analysis. Differential expression of functional groups of genes defined by standard gene ontology terms was also studied. There were substantial numbers of genes expressed more abundantly in ICC than in the tunica muscularis, and we also detected marked phenotypic differences between ICC-MY and ICC-DMP. Notably, genes related to cell junction, process guidance, and vesicle trafficking were upregulated in ICC. Consistent with their specific functions, metabolic and Ca(2+) transport genes were relatively upregulated in ICC-MY, whereas genes for signaling proteins involved in transduction of neurotransmitter functions were relatively upregulated in ICC-DMP. Our results may lead to the identification of novel biomarkers for ICC and provide directions for further studies designed to understand ICC function in health and disease.

Substance P induces inward current and regulates pacemaker currents through tachykinin NK 1 receptor in cultured interstitial cells of Cajal of murine small intestine

We investigated whether substance P modulates pacemaker currents generated in cultured interstitial cells of Cajal of murine small intestine using whole cell patch-clamp techniques at 30 °C. Interstitial cells of Cajal generated spontaneous inward currents (pacemaker currents) at a holding potential of −70 mV. Tetrodotoxin, nifedipine, tetraethylammonium, 4-aminopyridine, or glibenclamide did not change the frequency and amplitude of pacemaker currents. However, divalent cations (Ni 2+, Mn 2+, Cd 2+, and Co 2+), nonselective cationic channel blockers (gadolinium and flufenamic acid), and a reduction of external Na + from normal to 1 mM inhibited pacemaker currents indicating that nonselective cation channels are involved in their generation. Substance P depolarized the membrane potential in current clamp mode and produced tonic inward pacemaker currents with reduced frequency and amplitude in voltage clamp mode. [ d-Arg 1, d-Trp 7,9, Leu 11] substance P, a tachykinin NK 1 receptor antagonist, blocked these substance P-induced responses. Furthermore, [Sar 9, Met(O 2) 11] substance P, a specific tachykinin NK 1 receptor agonist, depolarized the membrane and tonic inward currents mimicked those of substance P. Substance P continued to produce tonic inward currents in external Ca 2+-free solution or in the presence of chelerythrine, a protein kinase C inhibitor. However, substance P-induced tonic inward currents were blocked by thapsigargin, a Ca 2+-ATPase inhibitor in the endoplasmic reticulum or by an external 1 mM Na + solution. Our results demonstrate that substance P may modulate intestinal motility by acting on the interstitial cells of Cajal by activating nonselective cation channels via the release of intracellular Ca 2+ induced by tachykinin NK 1 receptor stimulation.