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Filho FC, Silva JDP, Petri C, Almendra JSL, de Sousa ÍA, Cavalcanti SMG, Silva BA, Formiga Melo MF, Cavalcanti PMDS. Pharmacological evidence that GABA-induced relaxation of rat proximal duodenum longitudinal muscle depends on NKCC cotransporter activity and Ca 2+ influx. Can J Physiol Pharmacol 2022; 100:728-740. [PMID: 35880679 DOI: 10.1139/cjpp-2021-0639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in adult central nervous system (CNS) synapses, but it excites immature CNS neurons as well as neurons in the myenteric plexus. The present work aimed to determine whether GABA-induced nonadrenergic, noncholinergic (NANC) neuronal-mediated relaxation of the rat duodenum is dependent on the activity of Na+ K+ Cl- cotransporters (NKCC) and requires calcium influx. In the presence of guanethidine (3 µmol/L), atropine (3 µmol/L), and indomethacin (1 µmol/L), relaxations induced by GABA (100 µmol/L), KCl (5-10 mmol/L) and electrical field stimulation (1-8 Hz, 2 ms, 60 V), but not those induced by bradykinin (10-100 nmol/L) were abolished by lidocaine (300 µmol/L). However, only GABA-induced relaxations were reduced in a concentration-dependent manner by the NKCC1/2 inhibitors bumetanide (0.1-1 µmol/L) and furosemide (1-10 µmol/L). GABA-induced NANC neuronal relaxation was abolished by bicuculline (30 µmol/L) and inhibited by N-nitroarginine methyl ester (l-NAME, 300 µmol/L). The ω-conotoxin GVIA (1 µmol/L), which acts exclusively on neuronal CaV2 channels, but not on smooth muscle voltage-gated Ca2+ CaV1 channels, and nonselective blockers of these channels (verapamil 100 nmol/L and ruthenium red 10 µmol/L), reduced GABA-induced relaxations. These results showed that the activation of GABAA receptors induces NANC nitrergic neuronal relaxations in the rat duodenum, which depend on NKCC activity and CaV2 channel activation, suggesting that this phenomenon results from neuronal depolarization promoted by Cl- efflux through GABAA receptors, with subsequent Ca2+ influx and nitric oxide release.
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Affiliation(s)
- Francisco Chagas Filho
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | - Janyerson Dannys Pereira Silva
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | - Caio Petri
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | - João Santos Lima Almendra
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | - Ícaro Araújo de Sousa
- Biophysics and Physiology Department, 64049-550, Health Sciences Center, Federal University of Piauí, Teresina, Piauí, Brazil
| | | | - Bagnólia A Silva
- Pharmacological Sciences Department, 58051-900, Health Sciences Center, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Margareth Fátima Formiga Melo
- Pharmacological Sciences Department, 58051-900, Health Sciences Center, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
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Swain S, Gupta RK, Ratnayake K, Priyanka PD, Singh R, Jana S, Mitra K, Karunarathne A, Giri L. Confocal Imaging and k-Means Clustering of GABA B and mGluR Mediated Modulation of Ca 2+ Spiking in Hippocampal Neurons. ACS Chem Neurosci 2018; 9:3094-3107. [PMID: 30044088 DOI: 10.1021/acschemneuro.8b00297] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Imaging cytosolic calcium in neurons is emerging as a new tool in neurological disease diagnosis, drug screening, and toxicity testing. Ca2+ oscillation signatures show a significant variation depending on GPCR targeting agonists. Quantification of Ca2+ spike trains in ligand induced Ca2+ oscillations remains challenging due to their inherent heterogeneity in primary culture. Moreover, there is no framework available for identification of optimal number of clusters and distance metric to cluster Ca2+ spike trains. Using quantitative confocal imaging and clustering analysis, we show the characterization of Ca2+ spiking in GPCR targeting drug-treated primary culture of hippocampal neurons. A systematic framework for selection of the clustering method instead of an intuition-based method was used to optimize the cluster number and distance metric. The results discern neurons with diverse Ca2+ response patterns, including higher amplitude fast spiking and lower spiking responses, and their relative percentage in a neuron population in absence and presence of GPCR-targeted drugs. The proposed framework was employed to show that the clustering pattern of Ca2+ spiking can be controlled using GABAB and mGluR targeting drugs. This approach can be used for unbiased measurement of neural activity and identification of spiking population with varying amplitude and frequencies, providing a platform for high-content drug screening.
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Affiliation(s)
- Sarpras Swain
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Rishikesh Kumar Gupta
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Kasun Ratnayake
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Pantula Devi Priyanka
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Ranjana Singh
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Soumya Jana
- Department of Electrical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Kishalay Mitra
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Ajith Karunarathne
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Lopamudra Giri
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
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Koussoulas K, Swaminathan M, Fung C, Bornstein JC, Foong JPP. Neurally Released GABA Acts via GABA C Receptors to Modulate Ca 2+ Transients Evoked by Trains of Synaptic Inputs, but Not Responses Evoked by Single Stimuli, in Myenteric Neurons of Mouse Ileum. Front Physiol 2018; 9:97. [PMID: 29487540 PMCID: PMC5816811 DOI: 10.3389/fphys.2018.00097] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/29/2018] [Indexed: 12/16/2022] Open
Abstract
γ-Aminobutyric Acid (GABA) and its receptors, GABAA,B,C, are expressed in several locations along the gastrointestinal tract. Nevertheless, a role for GABA in enteric synaptic transmission remains elusive. In this study, we characterized the expression and function of GABA in the myenteric plexus of the mouse ileum. About 8% of all myenteric neurons were found to be GABA-immunoreactive (GABA+) including some Calretinin+ and some neuronal nitric oxide synthase (nNOS+) neurons. We used Wnt1-Cre;R26R-GCaMP3 mice, which express a genetically encoded fluorescent calcium indicator in all enteric neurons and glia. Exogenous GABA increased the intracellular calcium concentration, [Ca2+]i of some myenteric neurons including many that did not express GABA or nNOS (the majority), some GABA+, Calretinin+ or Neurofilament-M (NFM)+ but rarely nNOS+ neurons. GABA+ terminals contacted a significantly larger proportion of the cell body surface area of Calretinin+ neurons than of nNOS+ neurons. Numbers of neurons with GABA-induced [Ca2+]i transients were reduced by GABAA,B,C and nicotinic receptor blockade. Electrical stimulation of interganglionic fiber tracts was used to examine possible effects of endogenous GABA release. [Ca2+]i transients evoked by single pulses were unaffected by specific antagonists for each of the 3 GABA receptor subtypes. [Ca2+]i transients evoked by 20 pulse trains were significantly amplified by GABAC receptor blockade. These data suggest that GABAA and GABAB receptors are not involved in synaptic transmission, but suggest a novel role for GABAC receptors in modulating slow synaptic transmission, as indicated by changes in [Ca2+]i transients, within the ENS.
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Affiliation(s)
| | | | | | | | - Jaime P. P. Foong
- Department of Physiology, University of Melbourne, Parkville, VIC, Australia
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Antisecretory Factor Modulates GABA A Receptor Activity in Neurons. J Mol Neurosci 2018; 64:312-320. [PMID: 29308551 DOI: 10.1007/s12031-017-1024-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 12/22/2017] [Indexed: 10/18/2022]
Abstract
The antisecretory factor is an endogenous protein found in all mammalian tissues investigated so far. It acts by counteracting intestinal hypersecretion and various forms of inflammation, but the detailed mechanism of antisecretory factor (AF) action is unknown. We tested neuronal GABAA receptors by means of AF-16, a potent AF peptide derived from amino acids 36-51 from the NH2 part of AF. Cultured rat cerebellar granule cells were used, and the effects on the GABA-mediated chloride currents were determined by whole-cell patch clamp. Both the neurotransmitter GABA and AF-16 were added by perfusion of the experimental system. A 3-min AF-16 preincubation was more efficacious than 30 s in significantly elevating the rapidly desensitizing GABA-activated chloride current. No effect was found on the tonic, slowly desensitizing current. The GABA-activated current increase by AF-16 demonstrated a low k of 41 pM with a maximal increase of 37% persisting for some minutes after AF washout, independent from GABA concentration. This indicates an effect on the maximal stimulation (E%Max) excluding an altered affinity between GABA and its receptor. An immunocytochemical fluorescence approach with anti γ2 subunit antibodies demonstrated an increased expression of GABAA receptors. Thus, both the electrophysiological and the immunofluorescence approach indicate an increased appearance of GABAA receptors on the neuronal membrane. The rationale of the experiments was to test the effect of AF on a defined neuronal population of GABAA receptors. The implications of the results on the impact of AF on the enteric nervous system or on brain function are discussed.
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Maier A, Mannartz V, Wasmuth H, Trautwein C, Neumann UP, Weis J, Grosse J, Fuest M, Hilz MJ, Schulz JB, Haubrich C. GAD Antibodies as Key Link Between Chronic Intestinal Pseudoobstruction, Autonomic Neuropathy, and Limb Stiffness in a Nondiabetic Patient: A CARE-Compliant Case Report and Review of the Literature. Medicine (Baltimore) 2015; 94:e1265. [PMID: 26252289 PMCID: PMC4616576 DOI: 10.1097/md.0000000000001265] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Chronic intestinal pseudoobstruction (CIP) can be a severe burden and even a life-threatening disorder. Typically, several years of uncertainty are passing before diagnosis. We are reporting the case of a young woman with a decade of severe, progressive gastrointestinal dysmotility. Unusually, she had also developed an autonomic neuropathy, and a stiff limb syndrome.In addition to achalasia and CIP the young woman also developed neuropathic symptoms: orthostatic intolerance, urinary retention, a Horner syndrome, and lower limb stiffness. Careful interdisciplinary diagnostics excluded underlying infectious, rheumatoid, metabolic or tumorous diseases.The detection of GAD (glutamic acid decarboxylase) antibodies, however, seemed to link CIP, autonomic neuropathy, and limb stiffness and pointed at an autoimmune origin of our patient's complaints. This was supported by the positive effects of intravenous immunoglobulin. In response to this therapy the body weight had stabilized, orthostatic tolerance had improved, and limb stiffness was reversed.The case suggested that GAD antibodies should be considered in CIP also in nondiabetic patients. This may support earlier diagnosis and immunotherapy.
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Affiliation(s)
- Andrea Maier
- From the Department of Neurology (AM, VM, JBS, CH), University Hospital RWTH Aachen,; Department of Medicine (HW), Luisenhospital Aachen; Department of Gastroenterology (CT), University Hospital RWTH Aachen; Department of Visceral Surgery (U-PN), University Hospital RWTH Aachen; Institute of Neuropathology (JW), University Hospital RWTH Aachen; Department of Urology (JG), University Hospital RWTH Aachen; Department of Ophthalmology (MF), University Hospital RWTH Aachen); and Department of Neurology (M-JH), Erlangen University Hospital, Germany
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Unsaturated Analogues of the Neurotransmitter GABA: trans-4-Aminocrotonic, cis-4-Aminocrotonic and 4-Aminotetrolic Acids. Neurochem Res 2015; 41:476-80. [DOI: 10.1007/s11064-015-1619-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 05/15/2015] [Accepted: 05/18/2015] [Indexed: 10/23/2022]
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7
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Liu QY, Wang CY, Cai ZL, Xu ST, Liu WX, Xiao P, Li CH. Effects of intrahippocampal GABAB receptor antagonist treatment on the behavioral long-term potentiation and Y-maze learning performance. Neurobiol Learn Mem 2014; 114:26-31. [DOI: 10.1016/j.nlm.2014.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/28/2014] [Accepted: 04/01/2014] [Indexed: 01/10/2023]
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8
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Cheng ZY, Wang XP, Schmid KL, Han XG. GABAB1 and GABAB2 receptor subunits co-expressed in cultured human RPE cells regulate intracellular Ca2+ via Gi/o-protein and phospholipase C pathways. Neuroscience 2014; 280:254-61. [PMID: 25241062 DOI: 10.1016/j.neuroscience.2014.09.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/10/2014] [Accepted: 09/10/2014] [Indexed: 11/26/2022]
Abstract
GABAB receptors associate with Gi/o-proteins that regulate voltage-gated Ca(2+) channels and thus the intracellular Ca(2+) concentration ([Ca(2+)]i), there is also reported cross-regulation of phospholipase C. These associations have been studied extensively in the brain and also shown to occur in non-neural cells (e.g. human airway smooth muscle). More recently GABAB receptors have been observed in chick retinal pigment epithelium (RPE). The aims were to investigate whether the GABAB receptor subunits, GABAB1 and GABAB2, are co-expressed in cultured human RPE cells, and then determine if the GABAB receptor similarly regulates the [Ca(2+)]i of RPE cells and if phospholipase C is involved. Human RPE cells were cultured from five donor eye cups. Evidence for GABAB1 and GABAB2 mRNAs and proteins in the RPE cell cultures was investigated using real time polymerase chain reaction, western blots and immunofluorescence. The effects of the GABAB receptor agonist baclofen, antagonist CGP46381, a Gi/o-protein inhibitor pertussis toxin, and the phospholipase C inhibitor U73122 on [Ca(2+)]i in cultured human RPE were demonstrated using Fluo-3. Both GABAB1 and GABAB2 mRNA and protein were identified in cell cultures of human RPE; antibody staining was co-localized to the cell membrane and cytoplasm. One-hundred micromolars of baclofen caused a transient increase in the [Ca(2+)]i of RPE cells regardless of whether Ca(2+) was added to the buffer. Baclofen-induced increases in the [Ca(2+)]i were attenuated by pre-treatment with CGP46381, pertussis toxin, and U73122. GABAB1 and GABAB2 are co-expressed in cell cultures of human RPE. GABAB receptors in RPE regulate the [Ca(2+)]i via a Gi/o-protein and phospholipase C pathway.
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Affiliation(s)
- Z-Y Cheng
- Department of Ophthalmology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China.
| | - X-P Wang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - K L Schmid
- School of Optometry and Vision Science, Faculty of Health, and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD 4059, Australia
| | - X-G Han
- Department of Ophthalmology, The Second Hospital, Jinan, Shandong 250001, China
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9
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Juárez EH, Ochoa-Cortés F, Miranda-Morales M, Espinosa-Luna R, Montaño LM, Barajas-López C. Selectivity of antagonists for theCys-loop native receptors for ACh, 5-HT and GABA in guinea-pig myenteric neurons. ACTA ACUST UNITED AC 2013; 34:1-8. [DOI: 10.1111/aap.12016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 07/30/2013] [Accepted: 08/16/2013] [Indexed: 11/29/2022]
Affiliation(s)
- E. H. Juárez
- División de Biología Molecular; Instituto Potosino de Investigación Científica y Tecnológica; San Luis Potosí SLP México
| | - F. Ochoa-Cortés
- División de Biología Molecular; Instituto Potosino de Investigación Científica y Tecnológica; San Luis Potosí SLP México
| | - M. Miranda-Morales
- Departamento de Neurobiología Celular y Molecular; Instituto de Neurobiología; Universidad Nacional Autónoma de México; Campus Juriquilla Querétaro Querétaro México
| | - R. Espinosa-Luna
- División de Biología Molecular; Instituto Potosino de Investigación Científica y Tecnológica; San Luis Potosí SLP México
| | - L. M. Montaño
- Departamento de Farmacología; Facultad de Medicina; Universidad Nacional Autónoma de México; México DF México
| | - C. Barajas-López
- División de Biología Molecular; Instituto Potosino de Investigación Científica y Tecnológica; San Luis Potosí SLP México
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Zhang S, Hyrc K, Wang S, Wice BM. Xenin-25 increases cytosolic free calcium levels and acetylcholine release from a subset of myenteric neurons. Am J Physiol Gastrointest Liver Physiol 2012; 303:G1347-55. [PMID: 23086920 PMCID: PMC3532549 DOI: 10.1152/ajpgi.00116.2012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Xenin-25 (Xen) is a 25 amino acid neurotensin-related peptide reportedly produced with glucose-dependent insulinotropic polypeptide (GIP) by a subset of K cells in the proximal gut. We previously showed exogenously administered Xen, with GIP but not alone, increases insulin secretion in humans and mice. In mice, this effect is indirectly mediated via a central nervous system-independent cholinergic relay in the periphery. Xen also delays gastric emptying, reduces food intake, induces gall bladder contractions, and increases gut motility and secretion from the exocrine pancreas, suggesting that some effects of Xen could be mediated by myenteric neurons (MENs). To determine whether Xen activates these neurons, MENs were isolated from guinea pig proximal small intestines. Cells expressed neuronal markers and exhibited typical neuron-like morphology with extensive outgrowths emanating from cell bodies. Cytosolic free Ca(2+) levels ([Ca(2+)](i)) were measured using Fura-2. ATP/UTP, KCl, and forskolin increased [Ca(2+)](i) in 99.6%, 92%, and 23% of the MENs imaged, respectively, indicating that they are functional and activated by nucleotide receptor signaling, direct depolarization, and cAMP. [Ca(2+)](i) increased in only 12.7% of MENs treated with Xen. This rise was blocked by pretreatment with EGTA, diazoxide, SR48692, and neurotensin. Thus the Xen-mediated increase in [Ca(2+)](i) involves influx of extracellular Ca(2+) and activation of neurotensin receptor-1 (NTSR1). Xen also increased acetylcholine release from MENs. Amylin, produced by β-and enteroendocrine cells, delays gastric emptying and increased [Ca(2+)](i) almost exclusively in Xen-responsive MENs. Immunohistochemistry demonstrated NTSR1 expression in human duodenal MENs. Thus myenteric rather than central neurons could mediate some effects of Xen and amylin.
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Affiliation(s)
- Sheng Zhang
- Department of Internal Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri 63110, USA
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11
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Huang KH, Chang CC, Ho JD, Lu RH, Tsai LH. Role of taurine on acid secretion in the rat stomach. J Biomed Sci 2011; 18:11. [PMID: 21294907 PMCID: PMC3042912 DOI: 10.1186/1423-0127-18-11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 02/05/2011] [Indexed: 11/10/2022] Open
Abstract
Background Taurine has chemical structure similar to an inhibitory neurotransmitter, γ-aminobutyric acid (GABA). Previous studies on GABA in the stomach suggest GABAergic neuron is involved in acid secretion, but the effects of taurine are poor understood. Methods The effects of taurine on acid secretion, signal transduction, and localization of taurinergic neurons were determined in the rat stomach using everted whole stomach, RIA kit and immunohistochemical methods. Results We used antibodies against taurine-synthesizing enzyme, cysteine sulfuric acid decarboxylase (CSAD), and taurine. CSAD- and taurine-positive cells were found in the muscle and mucosal layers. Distributions of CSAD- and taurine-positive cells in both mucosal and muscle layers were heterogeneous in the stomach. Taurine at 10-9~10-4 M induced acid secretion, and the maximum secretion was at 10-5 M, 1.6-fold higher than the spontaneous secretion. Taurine-induced acid secretion was completely inhibited by bicuculline and atropine but not by cimetidine, proglumide, or strychnine. Atropine and tetrodotoxin (TTX) completely inhibited the acid secretion induced by low concentrations of taurine and partially inhibited induced by high concentrations. Verapamil, a calcium blocker agent, inhibited acid output elicited by taurine. We assumed all Ca2+ channels involved in the response to these secretagogues were equally affected by verapamil. Intracellular cAMP (adenosine 3', 5'-monophosphat) in the stomach significantly increased with taurine treatment in a dose-dependent manner. High correlation (r=0.859, p < 0.001) of taurine concentrations with cAMP was observed. Conclusions Our results demonstrated for the first time in taurine-induced acid secretion due to increase intracellular calcium may act through the A type of GABA receptors, which are mainly located on cholinergic neurons though cAMP pathway and partially on nonneuronal cells in the rat stomach.
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Affiliation(s)
- Kai-Han Huang
- Department of Ophthalmology, Taipei Medical University Hospital, Taipei Taiwan
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12
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Kraichely RE, Farrugia G, Pittock SJ, Castell DO, Lennon VA. Neural autoantibody profile of primary achalasia. Dig Dis Sci 2010; 55:307-11. [PMID: 19499338 PMCID: PMC2819289 DOI: 10.1007/s10620-009-0838-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 04/30/2009] [Indexed: 12/12/2022]
Abstract
The etiology and pathogenesis of primary achalasia are both unknown. Postulated mechanisms include autoimmune, viral-immune, and central neurodegenerative. The aim of this study is to investigate the serum profile of neural autoantibodies in patients with primary achalasia. Coded sera from 70 patients with primary achalasia and 161 healthy control subjects, matched in sex, age, and smoking habits, were screened for antibodies targeting neuronal, glial, and muscle autoantigens. No specific myenteric neuronal antibody was identified. However, the overall prevalence of neural autoantibodies in patients with primary achalasia was significantly higher than in healthy control subjects (25.7 vs. 4.4%, P < 0.0001). Most noteworthy was the 21.4% frequency of glutamic acid decarboxylase-65 antibody in patients with achalasia (versus 2.5% in control subjects), in the absence of diabetes or companion antibodies predictive of type 1 diabetes. This profile of autoantibodies suggests an autoimmune basis for a subset of primary achalasia.
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Affiliation(s)
- Robert E. Kraichely
- Enteric NeuroScience Program, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN
| | - Gianrico Farrugia
- Enteric NeuroScience Program, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN
| | - Sean J. Pittock
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN
| | | | - Vanda A. Lennon
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN
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Reis HJ, Rosa DVF, Guimarães MM, Souza BR, Barros AGA, Pimenta FJ, Souza RP, Torres KCL, Romano-Silva MA. Is DARPP-32 a potential therapeutic target? Expert Opin Ther Targets 2007; 11:1649-61. [DOI: 10.1517/14728222.11.12.1649] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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14
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Ercoli J, Miolan JP, Niel JP, Quinson N. Presynaptic GABA-A receptors prevent depression of nicotinic transmission in rabbit coeliac ganglion neurones. Eur J Neurosci 2007; 25:1307-18. [PMID: 17425557 DOI: 10.1111/j.1460-9568.2007.05382.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We investigated the involvement of GABA-A receptors in the modulation of the nicotinic transmission of central origin in isolated rabbit coeliac ganglia. Our study was performed in vitro and the electrical activity of the ganglionic neurones was recorded using intracellular recording techniques. During iterative stimulation of the splanchnic nerves, the synaptic action potential probability decreased gradually, indicating a depression of the nicotinic activation. Pharmacological agents acting at GABA-A receptors modulated the action potential probability during the train of pulses. Muscimol (a GABA-A receptor agonist), diazepam (a benzodiazepine site agonist) and 1-[2-[[(diphenylmethylene)imino]oxy]ethyl]-1,2,5,6-tetrahydro-3-pyridinecarboxylic acid hydrochloride (a GABA uptake blocker) increased this probability. Conversely, gabazine or bicuculline (two GABA-A receptor antagonists), picrotoxin (a picrotoxin site agonist) and flumazenil (a benzodiazepine site antagonist) reduced it. These results demonstrate that endogenous GABA, released during the train of pulses, facilitates the central nicotinic activation of the ganglionic neurones by acting on GABA-A receptors. Muscimol also reduced the amplitude ratio of excitatory postsynaptic potentials triggered during the paired-pulse protocol without any change in postsynaptic properties. This result is consistent with a presynaptic action of GABA-A receptors. Our study shows that presynaptic GABA-A receptors facilitate the central nicotinic activation of prevertebral ganglionic neurones and thus play a novel role in the integrative properties of the sympathetic prevertebral ganglia.
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Affiliation(s)
- Jennifer Ercoli
- Laboratoire de Physiologie Neurovégétative, UMR Université Paul Cézanne Aix-Marseille III-CNRS-INRA, Faculté des Sciences et Techniques, 13397 Marseille cedex 20, France
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