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Zhao Y, Luo H, Ren X, Jia B, Li J, Wang L, Li J. The P2Y 1 receptor in the colonic myenteric plexus of rats and its correlation with opioid-induced constipation. BMC Gastroenterol 2024; 24:23. [PMID: 38191294 PMCID: PMC10773096 DOI: 10.1186/s12876-024-03119-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 01/01/2024] [Indexed: 01/10/2024] Open
Abstract
This study was designed to explore the expression changes of P2Y1 receptors in the distal colonic myenteric layer of rats. An opioid induced constipation(OIC) rat model was generated by intraperitoneal (i.p) injection of loperamide. At 7 days post-treatment, the model rats were assessed by calculating the fecal water content and the gastrointestinal transit ratio. The immunofluorescence (IF)-based histochemical study was used to observe the distribution of P2Y1 receptors in the distal colonic myenteric plexus. Western blotting (WB) was performed to evaluate the expression changes of P2Y1 proteins in the myenteric layer, and the electrophysiological approaches were carried out to determine the regulatory roles of P2Y1 receptors on distal colonic motor function. IF showed that P2Y1 receptors are co-expressed MOR in the enteric nerve cells of the distal colonic myenteric plexus. Moreover, the WB revealed that the protein levels of P2Y1 were significantly decreased in the distal colonic myenteric layer of OIC rats. In vitro tension experiments exhibited that the P2Y1 receptor antagonist MRS2500 enhanced the spontaneous contraction amplitude, adding EM2 and β-FNA did not have any effect on MRS2500. Therefore, P2Y1 receptor expression could be associated with the occurrence of OIC in this rat model and the regulation of colonic motility by MOR may be related to the release of purine neurotransmitters such as ATP in the colonic nervous system.
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Affiliation(s)
- Yuqiong Zhao
- Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, 750001, Yinchuan, Ningxia Hui Autonomous Region, P.R. China
| | - Huijuan Luo
- Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, 750001, Yinchuan, Ningxia Hui Autonomous Region, P.R. China
| | - Xiaojie Ren
- Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, 750001, Yinchuan, Ningxia Hui Autonomous Region, P.R. China
| | - Binghan Jia
- Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, 750001, Yinchuan, Ningxia Hui Autonomous Region, P.R. China
| | - Jinzhao Li
- Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, 750001, Yinchuan, Ningxia Hui Autonomous Region, P.R. China
| | - Lixin Wang
- The Medical Laboratory Center of General Hospital of Ningxia Medical University, 804 Shengli Street, 750001, Yinchuan, Ningxia Hui Autonomous Region, P.R. China.
| | - Junping Li
- Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Ningxia Medical University, 1160 Shengli Street, 750001, Yinchuan, Ningxia Hui Autonomous Region, P.R. China.
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Lu Y, Huang J, Zhang Y, Huang Z, Yan W, Zhou T, Wang Z, Liao L, Cao H, Tan B. Therapeutic Effects of Berberine Hydrochloride on Stress-Induced Diarrhea-Predominant Irritable Bowel Syndrome Rats by Inhibiting Neurotransmission in Colonic Smooth Muscle. Front Pharmacol 2021; 12:596686. [PMID: 34594213 PMCID: PMC8476869 DOI: 10.3389/fphar.2021.596686] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 09/01/2021] [Indexed: 11/13/2022] Open
Abstract
The etiology of diarrhea-predominant irritable bowel syndrome (IBS-D) is complicated and closely related to neurotransmission in the gastrointestinal (GI) tract. Developing new strategies for treating this disease is a major challenge for IBS-D research. Berberine hydrochloride (BBH), the derivative of berberine, is a herbal constituent used to treat IBS. Previous studies have shown that BBH has potential anti-inflammatory, antibacterial, analgesic, and antidiarrheal effects and a wide range of biological activities, especially in regulating the release of some neurotransmitters. A modified IBS-D rat model induced by chronic restraint stress was used in all experiments to study the effects of BBH on the GI tract. This study measured the abdominal withdrawal reflex (AWR) response to graded colorectal distention (CRD; 20, 40, 60, and 80 mmHg) and observed the fecal areas of stress-induced IBS-D model. Experiments were conducted using organ bath techniques, which were performed in vitro using strips of colonic longitudinal smooth muscle. Inhibitory and excitatory neurotransmitter agents were added to each organ bath to observe contractile responses on the strips and the treatment effect exerted by BBH. The IBS-D rat model was successfully induced by chronic restraint stress, which resulted in an increased defecation frequency and visceral hypersensitivity similar to that of humans. BBH could reduce 4-h fecal areas and AWR response to CRD in IBS-D. The stress-induced IBS-D model showed upregulated colonic mRNA expression levels of 5-hydroxytryptamine-3A receptor and downregulated expression levels of neuronal nitric oxide synthase. Meanwhile, BBH could reverse this outcome. The responses of substances that regulate the contraction induced by related neurotransmission in the longitudinal smooth muscle of IBS-D colon (including the agonist of acetylcholine, carbachol; NOS inhibitor, L-NAME; and P2Y1 receptor antagonist, MRS2500) can be inhibited by BBH. In summary, BBH promotes defecation frequency and visceral hypersensitivity in IBS-D and exerts inhibitory effects on contractile responses in colonic longitudinal smooth muscle. Thus, BBH may represent a new therapeutic approach for treating IBS-D.
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Affiliation(s)
- Yulin Lu
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jingjing Huang
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yao Zhang
- School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zitong Huang
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Weiming Yan
- The Third Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Tianran Zhou
- The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
| | - Zhesheng Wang
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Lu Liao
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Hongying Cao
- School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Bo Tan
- Research Center for Integrative Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
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Traserra S, Barber C, Maclnnes J, Relea L, MacPherson LC, Cunningham MR, Vergara P, Accarino A, Kennedy C, Jimenez M. Different responses of the blockade of the P2Y1 receptor with BPTU in human and porcine intestinal tissues and in cell cultures. Neurogastroenterol Motil 2021; 33:e14101. [PMID: 33619847 DOI: 10.1111/nmo.14101] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 01/11/2021] [Accepted: 01/26/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND Gastrointestinal smooth muscle relaxation is accomplished by activation of P2Y1 receptors, therefore this receptor plays an important role in regulation of gut motility. Recently, BPTU was developed as a negative allosteric modulator of the P2Y1 receptor. Accordingly, the aim of this study was to assess the effect of BPTU on purinergic neurotransmission in pig and human gastrointestinal tissues. METHODS Ca2+ imaging in tSA201 cells that express the human P2Y1 receptor, organ bath and microelectrodes in tissues were used to evaluate the effects of BPTU on purinergic responses. KEY RESULTS BPTU concentration dependently (0.1 and 1 µmol L-1 ) inhibited the rise in intracellular Ca2+ evoked by ADP in tSA201 cells. In the pig small intestine, 30 µmol L-1 BPTU reduced the fast inhibitory junction potential by 80%. Smooth muscle relaxations induced by electrical field stimulation were reduced both in pig ileum (EC50 = 6 µmol L-1 ) and colon (EC50 = 35 µmol L-1 ), but high concentrations of BPTU (up to 100 µmol L-1 ) had no effect on human colonic muscle. MRS2500 (1 µmol L-1 ) abolished all responses. Finally, 10 µmol L-1 ADPβS inhibited spontaneous motility and this was partially reversed by 30 µmol L-1 BPTU in pig, but not human colonic tissue and abolished by MRS2500 (1 µmol L-1 ). CONCLUSIONS & INFERENCES BPTU blocks purinergic responses elicited via P2Y1 receptors in cell cultures and in pig gastrointestinal tissue. However, the concentrations needed are higher in pig tissue compared to cell cultures and BPTU was ineffective in human colonic tissue.
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Affiliation(s)
- Sara Traserra
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Claudia Barber
- Digestive System Research Unit, University Hospital Vall d'Hebron, Barcelona, Spain
| | - Jane Maclnnes
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Lucia Relea
- Digestive System Research Unit, University Hospital Vall d'Hebron, Barcelona, Spain
| | - Lewis C MacPherson
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Margaret R Cunningham
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Patri Vergara
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd),, Instituto de Salud Carlos III, Madrid, Spain
| | - Anna Accarino
- Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd),, Instituto de Salud Carlos III, Madrid, Spain.,Digestive System Research Unit, University Hospital Vall d'Hebron, Barcelona, Spain
| | - Charles Kennedy
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Marcel Jimenez
- Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd),, Instituto de Salud Carlos III, Madrid, Spain
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Diadenosine tetraphosphate activates P2Y 1 receptors that cause smooth muscle relaxation in the mouse colon. Eur J Pharmacol 2019; 855:160-166. [PMID: 31063775 DOI: 10.1016/j.ejphar.2019.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 05/03/2019] [Accepted: 05/03/2019] [Indexed: 01/01/2023]
Abstract
P2Y1 receptors play an essential role in inhibitory neuromuscular transmission in the gastrointestinal tract. The signalling pathway involves the opening of small conductance calcium activated potassium-channels (Kca2 family) that results in smooth muscle hyperpolarization and relaxation. Inorganic polyphosphates and dinucleotidic polyphosphates are putative neurotransmitters that potentially act on P2Y1 receptors. A pharmacological approach using both orthosteric (MRS2500) and allosteric (BPTU) blockers of the P2Y1 receptor and openers (CyPPA) and blockers (apamin) of Kca2 channels was used to pharmacologically characterise the effect of these neurotransmitters. Organ bath and microelectrodes were used to evaluate the effect of P1,P4-Di (adenosine-5') tetraphosphate ammonium salt (Ap4A), inorganic polyphosphates (PolyP) and CyPPA on spontaneous contractions and membrane potential of mouse colonic smooth muscle cells. PolyP neither modified contractions nor membrane potential. In contrast, Ap4A caused a concentration-dependent inhibition of spontaneous contractions reaching a maximum effect at 100 μM Ap4A response was antagonised by MRS2500 (1 μM), BPTU (3 μM) and apamin (1 μM). CyPPA (10 μM) inhibited spontaneous contractions and this response was antagonised by apamin but it was not affected by MRS2500 or BPTU. Both CyPPA and Ap4A caused smooth muscle hyperpolarization that was blocked by apamin and MRS2500 respectively. We conclude that Ap4A but not PolyP activates P2Y1 receptors causing smooth muscle hyperpolarization and relaxation. Ap4A signalling causes activation of Kca2 channels through activation of P2Y1 receptors. In contrast, CyPPA acts directly on Kca2 channels. Further studies are needed to evaluate if dinucleotidic polyphosphates are released from inhibitory motor neurons.
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Park IK, Kim JH, Park CG, Kim MY, Parajuli SP, Hong CS, Choi S, Jun JY. Effects of ATP on Pacemaker Activity of Interstitial Cells of Cajal from the Mouse Small Intestine. Chonnam Med J 2018; 54:63-71. [PMID: 29399568 PMCID: PMC5794481 DOI: 10.4068/cmj.2018.54.1.63] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 01/23/2023] Open
Abstract
Purinergic receptors play an important role in regulating gastrointestinal (GI) motility. Interstitial cells of Cajal (ICCs) are pacemaker cells that regulate GI smooth muscle activity. We studied the functional roles of external adenosine 5′-triphosphate (ATP) on pacemaker activity in cultured ICCs from mouse small intestines by using the whole-cell patch clamp technique and intracellular Ca2+ ([Ca2+]i) imaging. External ATP dose-dependently depolarized the resting membrane and produced tonic inward pacemaker currents, and these effects were antagonized by suramin, a purinergic P2 receptor antagonist. ATP-induced effects on pacemaker currents were suppressed by an external Na+-free solution and inhibited by the nonselective cation channel blockers, flufenamic acid and niflumic acid. The removal of external Ca2+ or treatment with thapsigargin (inhibitor of Ca2+ uptake into endoplasmic reticulum) inhibited the ATP-induced effects on pacemaker currents. Spontaneous [Ca2+]i oscillations were enhanced by external ATP. These results suggest that external ATP modulates pacemaker activity by activating nonselective cation channels via external Ca2+ influx and [Ca2+]i release from the endoplasmic reticulum. Thus, it seems that activating the purinergic P2 receptor may modulate GI motility by acting on ICCs in the small intestine.
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Affiliation(s)
- Il Koo Park
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | - Jin Ho Kim
- Department of Neurology, College of Medicine, Chosun University, Gwangju, Korea
| | - Chan Guk Park
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | - Man Yoo Kim
- Department of Internal Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | | | - Chan Sik Hong
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Seok Choi
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Jae Yeoul Jun
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
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He XD, Guo YM, Goyal RK. Effect of Hyperglycemia on Purinergic and Nitrergic Inhibitory Neuromuscular Transmission in the Antrum of the Stomach: Implications for Fast Gastric Emptying. Front Med (Lausanne) 2018; 5:1. [PMID: 29410956 PMCID: PMC5787141 DOI: 10.3389/fmed.2018.00001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 01/03/2018] [Indexed: 12/27/2022] Open
Abstract
Background Hyperglycemia has been reported to enhance vagovagal reflex that causes the release of inhibitory neurotransmitter, nitric oxide (NO), at the neuromuscular junction in the antrum to relax the antrum and slow gastric emptying by stimulating glucose-sensitive afferent neurons. However, hyperglycemia has also been reported to cause fast gastric emptying that may be due to suppression of the inhibitory motor neurons. Aims The purpose of the present study was to investigate changes in inhibitory neuromuscular transmission in the gastric antrum due to hyperglycemia. Methods Inhibitory electrical junction potentials were recorded from gastric antral muscle strips, using intracellular electrodes under non-adrenergic, non-cholinergic conditions. Studies were performed in non-hyperglycemic NOD (NH-NOD), NOD mice as they develop hyperglycemia (H-NOD) and their age-matched controls. The purinergic inhibitory junction potential (pIJP) and nitrergic IJP (nIJP) were isolated pharmacologically. Results The control pIJP was large, around −18 mV and nIJP was small, around −9 mV. In NH-NOD the IJPs were not affected, but in H-NOD pIJP was nearly abolished and nIJP was significantly reduced. In H-NOD mice, membrane hyperpolarization caused by exogenous α,β-MeATP or diethylenetriamine NO adduct was similar to that in wild-type controls (P > 0.05). H-NOD smooth muscles were significantly depolarized as compared to NH-NOD smooth muscles. Conclusion These observations show that hyperglycemia causes suppression of purinergic and nitrergic transmission by acting on the motor neurons that form the last neuron in the vagovagal circuit. Moreover, the loss the neurotransmission is due to a defect in neurotransmitter release rather than a defect in signal transduction. Hyperglycemia also causes depolarization of smooth muscles that may increase their excitability.
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Affiliation(s)
- Xue-Dao He
- Department of Medicine VA Boston Healthcare System, Harvard Medical School, Boston, MA, United States
| | - Yan-Mei Guo
- Department of Medicine VA Boston Healthcare System, Harvard Medical School, Boston, MA, United States
| | - Raj K Goyal
- Department of Medicine VA Boston Healthcare System, Harvard Medical School, Boston, MA, United States
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Durnin L, Moreland N, Lees A, Mutafova-Yambolieva VN. A commonly used ecto-ATPase inhibitor, ARL-67156, blocks degradation of ADP more than the degradation of ATP in murine colon. Neurogastroenterol Motil 2016; 28:1370-81. [PMID: 27060478 PMCID: PMC5002237 DOI: 10.1111/nmo.12836] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 03/14/2016] [Indexed: 01/24/2023]
Abstract
BACKGROUND Adenosine 5'-triphosphate (ATP) is released extracellularly as a neurotransmitter and an autocrine or paracrine mediator in numerous systems, including the gastrointestinal tract. It is rapidly degraded to active and inactive metabolites by membrane-bound enzymes. Investigators frequently use inhibitors of ATP hydrolysis such as ARL-67156 and POM-1 to suppress the catabolism of ATP and prolong its effects in pharmacological studies. Our aim was to investigate directly the effects of ARL-67156 and POM-1 on the degradation of ATP and adenosine 5'-diphosphate (ADP) in mouse colonic muscles. METHODS The degradation of ATP and ADP was evaluated by superfusing tissues with 1,N(6) -etheno-ATP (eATP) and 1,N(6) -etheno-ADP (eADP) as substrates and monitoring the decrease in substrate and increase in products (i.e., eADP, eAMP, and e-adenosine) by high-performance liquid chromatography techniques with fluorescence detection. Relaxation responses to etheno-derivatized and non-derivatized ATP and ADP were examined in isometric tension experiments. KEY RESULTS ARL-67156 inhibits the degradation of ADP but not of ATP, whereas POM-1 inhibits the degradation of ATP but not of ADP in murine colonic muscles. Consequently, ARL-67156 enhances relaxation responses to both ATP and ADP, whereas POM-1 reduces relaxation to ATP and does not affect relaxation to ADP. CONCLUSIONS & INFERENCES Studies that use ARL-67156 to inhibit ATP degradation in smooth muscle likely evaluate responses to accumulated ADP rather than ATP. POM-1 appears to be a more selective inhibitor of ATP degradation in the mouse colon. The choice of pharmacological tools in studies on extracellular ATP signaling may affect the interpretation of experimental data in functional studies.
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Affiliation(s)
- L. Durnin
- Department of Physiology and Cell Biology; University of Nevada School of Medicine; Reno NV USA
| | - N. Moreland
- Department of Physiology and Cell Biology; University of Nevada School of Medicine; Reno NV USA
| | - A. Lees
- Department of Physiology and Cell Biology; University of Nevada School of Medicine; Reno NV USA
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Mañé N, Jiménez-Sábado V, Jiménez M. BPTU, an allosteric antagonist of P2Y1 receptor, blocks nerve mediated inhibitory neuromuscular responses in the gastrointestinal tract of rodents. Neuropharmacology 2016; 110:376-385. [PMID: 27496690 DOI: 10.1016/j.neuropharm.2016.07.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 06/28/2016] [Accepted: 07/26/2016] [Indexed: 12/28/2022]
Abstract
P2Y1 receptors mediate nerve mediated purinergic inhibitory junction potentials (IJP) and relaxations in the gastrointestinal (GI) tract in a wide range of species including rodents and humans. A new P2Y1 antagonist, with a non-nucleotide structure, BPTU, has recently been described using X-ray crystallography as the first allosteric G-protein-coupled receptor antagonist located entirely outside of the helical bundle. In this study, we tested its effect on purinergic responses in the gastrointestinal tract of rodents using electrophysiological and myographic techniques. BPTU concentration dependently inhibited purinergic inhibitory junction potentials and inhibition of spontaneous motility induced by electrical field stimulation in the colon of rats (EC50 = 0.3 μM) and mice (EC50 = 0.06 μM). Mechanical inhibitory responses were also concentration-dependently blocked in the stomach of both species. Compared to MRS2500, BPTU displays a lower potency. In the rat colon nicotine induced relaxation was also blocked by BPTU. BPTU also blocked the cessation of spontaneous contractility elicited by ADPβS and the P2Y1 agonist MRS2365. We conclude that BPTU is a novel antagonist with different structural and functional properties than nucleotidic antagonists that is able to block the P2Y1 receptor located at the neuromuscular junction of the GI tract.
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Affiliation(s)
- Noemí Mañé
- Department of Cell Biology, Physiology and Immunology and Neuroscience Institute, Universitat Autònoma de Barcelona, Barcelona, Spain.
| | - Verónica Jiménez-Sábado
- Department of Cell Biology, Physiology and Immunology and Neuroscience Institute, Universitat Autònoma de Barcelona, Barcelona, Spain.
| | - Marcel Jiménez
- Department of Cell Biology, Physiology and Immunology and Neuroscience Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, (CIBERehd), Instituto de Salud Carlos III, Barcelona, Spain.
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9
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P2Y receptor-mediated transient relaxation of rat longitudinal ileum preparations involves phospholipase C activation, intracellular Ca(2+) release and SK channel activation. Acta Pharmacol Sin 2016; 37:617-28. [PMID: 27018177 DOI: 10.1038/aps.2015.137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 12/10/2015] [Indexed: 12/13/2022] Open
Abstract
AIM Purinergic signaling plays a major role in the enteric nervous system, where it governs gut motility through a number of P2X and P2Y receptors. The aim of this study was to investigate the P2Y receptor-mediated motility in rat longitudinal ileum preparations. METHODS Ileum smooth muscle strips were prepared from rats, and fixed in an organ bath. Isometric contraction and relaxation responses of the muscle strips were measured with force transducers. Drugs were applied by adding of stock solutions to the organ bath to yield the individual final concentrations. RESULTS Application of the non-hydrolyzable P2 receptor agonists α,β-Me-ATP or 2-Me-S-ADP (10, 100 μmol/L) dose-dependently elicited a transient relaxation response followed by a sustained contraction. The relaxation response was largely blocked by SK channel blockers apamin (500 nmol/L) and UCL1684 (10 μmol/L), PLC inhibitor U73122 (100 μmol/L), IP3 receptor blocker 2-APB (100 μmol/L) or sarcoendoplasmic Ca(2+) ATPase inhibitor thapsigargin (1 μmol/L), but not affected by atropine, NO synthase blocker L-NAME or tetrodotoxin. Furthermore, α,β-Me-ATP-induced relaxation was suppressed by P2Y1 receptor antagonist MRS2179 (50 μmol/L) or P2Y13 receptor antagonist MRS2211 (100 μmol/L), and was abolished by co-application of the two antagonists, whereas 2-Me-S-ADP-induced relaxation was abolished by P2Y6 receptor antagonist MRS2578 (50 μmol/L). In addition, P2Y1 receptor antagonist MRS2500 (1 μmol/L) not only abolished α,β-Me-ATP-induced relaxation, but also suppressed 2-Me-S-ADP-induced relaxation. CONCLUSION P2Y receptor agonist-induced transient relaxation of rat ileum smooth muscle strips is mediated predominantly by P2Y1 receptor, but also by P2Y6 and P2Y13 receptors, and involves PLC, IP3, Ca(2+) release and SK channel activation, but is independent of acetylcholine and NO release.
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Mas M, Mañé N, Fernández F, Gallego D, Pumarola M, Jiménez M. P2Y(1) receptors mediate purinergic relaxation in the equine pelvic flexure. Vet J 2016; 209:74-81. [PMID: 26831180 DOI: 10.1016/j.tvjl.2016.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 11/11/2015] [Accepted: 01/01/2016] [Indexed: 12/12/2022]
Abstract
In the equine large intestine, the knowledge of the basic mechanisms underlying motility function is crucial to properly treat motility disorders. P2Y1 receptors are responsible for mediating purinergic colonic relaxation in several species. In vitro experimental studies of the circular muscle from the equine pelvic flexure (n = 6) were performed to characterize inhibitory and excitatory neuromuscular transmission. Electrophysiological studies showed that electrical field stimulation (EFS) evoked biphasic inhibitory junction potentials (IJPs) in smooth muscle cells: a fast IJP (IJPf) followed by a sustained IJP (IJPs). IJPs was sensitive to L-NNA 1 mM (a nitric oxide synthase inhibitor) (P <0.01), while IJPf was abolished by MRS2500 1 µM (a P2Y1 receptor antagonist) (P <0.001). EFS (5 Hz for 2 min) in the organ bath inhibited rhythmic contractions to 3.0 ± 2.5% of basal area under the curve (P <0.0001). EFS under MRS2500 1 µM or L-NNA 1 mM incubation inhibited contractions to 6.0 ± 2.8% (P <0.05) and 24.4 ± 11.3% respectively (P <0.05). Combination of MRS2500 1 µM and L-NNA 1 mM completely reversed the EFS-induced inhibition of colonic motility. Non-nitrergic, non-purinergic conditions were used to reveal voltage-dependent EFS-induced contractions sensitive to atropine 1 µM (P <0.001) and, therefore, cholinergic. In conclusion, nerve-mediated relaxation and contraction in the equine pelvic flexure involve the same mechanisms as those observed in the human colon. P2Y1 receptors mediate purinergic relaxations and are potential targets for the treatment of equine colonic motor disorders.
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Affiliation(s)
- M Mas
- Department of Cell Biology, Physiology and Immunology and Neuroscience Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - N Mañé
- Department of Cell Biology, Physiology and Immunology and Neuroscience Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - F Fernández
- Department of Animal Medicine and Surgery, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - D Gallego
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Barcelona, Spain
| | - M Pumarola
- Department of Animal Medicine and Surgery, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - M Jiménez
- Department of Cell Biology, Physiology and Immunology and Neuroscience Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Barcelona, Spain.
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Upregulated P2X3 Receptor Expression in Patients with Intractable Temporal Lobe Epilepsy and in a Rat Model of Epilepsy. Neurochem Res 2016; 41:1263-73. [DOI: 10.1007/s11064-015-1820-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 12/24/2015] [Accepted: 12/29/2015] [Indexed: 12/11/2022]
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12
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Affiliation(s)
- Jackie D. Wood
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
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