1
|
Mutafova-Yambolieva VN, Durnin L. The purinergic neurotransmitter revisited: a single substance or multiple players? Pharmacol Ther 2014; 144:162-91. [PMID: 24887688 PMCID: PMC4185222 DOI: 10.1016/j.pharmthera.2014.05.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 05/23/2014] [Indexed: 12/20/2022]
Abstract
The past half century has witnessed tremendous advances in our understanding of extracellular purinergic signaling pathways. Purinergic neurotransmission, in particular, has emerged as a key contributor in the efficient control mechanisms in the nervous system. The identity of the purine neurotransmitter, however, remains controversial. Identifying it is difficult because purines are present in all cell types, have a large variety of cell sources, and are released via numerous pathways. Moreover, studies on purinergic neurotransmission have relied heavily on indirect measurements of integrated postjunctional responses that do not provide direct information for neurotransmitter identity. This paper discusses experimental support for adenosine 5'-triphosphate (ATP) as a neurotransmitter and recent evidence for possible contribution of other purines, in addition to or instead of ATP, in chemical neurotransmission in the peripheral, enteric and central nervous systems. Sites of release and action of purines in model systems such as vas deferens, blood vessels, urinary bladder and chromaffin cells are discussed. This is preceded by a brief discussion of studies demonstrating storage of purines in synaptic vesicles. We examine recent evidence for cell type targets (e.g., smooth muscle cells, interstitial cells, neurons and glia) for purine neurotransmitters in different systems. This is followed by brief discussion of mechanisms of terminating the action of purine neurotransmitters, including extracellular nucleotide hydrolysis and possible salvage and reuptake in the cell. The significance of direct neurotransmitter release measurements is highlighted. Possibilities for involvement of multiple purines (e.g., ATP, ADP, NAD(+), ADP-ribose, adenosine, and diadenosine polyphosphates) in neurotransmission are considered throughout.
Collapse
Affiliation(s)
| | - Leonie Durnin
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, United States
| |
Collapse
|
2
|
Lalo U, Verkhratsky A, Burnstock G, Pankratov Y. P2X receptor-mediated synaptic transmission. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/wmts.28] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
3
|
Burnstock G, Fredholm BB, North RA, Verkhratsky A. The birth and postnatal development of purinergic signalling. Acta Physiol (Oxf) 2010; 199:93-147. [PMID: 20345419 DOI: 10.1111/j.1748-1716.2010.02114.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The purinergic signalling system is one of the most ancient and arguably the most widespread intercellular signalling system in living tissues. In this review we present a detailed account of the early developments and current status of purinergic signalling. We summarize the current knowledge on purinoceptors, their distribution and role in signal transduction in various tissues in physiological and pathophysiological conditions.
Collapse
Affiliation(s)
- G Burnstock
- Autonomic Neuroscience Centre, Royal Free and University College Medical School, London, UK.
| | | | | | | |
Collapse
|
4
|
Pankratov Y, Lalo U, Krishtal OA, Verkhratsky A. P2X receptors and synaptic plasticity. Neuroscience 2008; 158:137-48. [PMID: 18495357 DOI: 10.1016/j.neuroscience.2008.03.076] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 03/09/2008] [Accepted: 03/17/2008] [Indexed: 01/15/2023]
Abstract
Adenosine triphosphate (ATP) is released in many synapses in the CNS either together with other neurotransmitters, such as glutamate and GABA, or on its own. Postsynaptic action of ATP is mediated through metabotropic P2Y and ionotropic P2X receptors abundantly expressed in neural cells. Activation of P2X receptors induces fast excitatory postsynaptic currents in synapses located in various brain regions, including medial habenula, hippocampus and cortex. P2X receptors display relatively high Ca2+ permeability and can mediate substantial Ca2+ influx at resting membrane potential. P2X receptors can dynamically interact with other neurotransmitter receptors, including N-methyl-D-aspartate (NMDA) receptors, GABA(A) receptors and nicotinic acetylcholine (ACh) receptors. Activation of P2X receptors has multiple modulatory effects on synaptic plasticity, either inhibiting or facilitating the long-term changes of synaptic strength depending on physiological context. At the same time precise mechanisms of P2X-dependent regulation of synaptic plasticity remain elusive. Further understanding of the role of P2X receptors in regulation of synaptic transmission in the CNS requires dissection of P2X-mediated effects on pre-synaptic terminals, postsynaptic membrane and glial cells.
Collapse
Affiliation(s)
- Y Pankratov
- The University of Warwick, Department of Biological Sciences, Gibbet Hill Road, Coventry CV4 7AL, UK
| | | | | | | |
Collapse
|
5
|
Kirmse K, Dvorzhak A, Grantyn R, Kirischuk S. Developmental downregulation of excitatory GABAergic transmission in neocortical layer I via presynaptic adenosine A(1) receptors. Cereb Cortex 2007; 18:424-32. [PMID: 17556770 DOI: 10.1093/cercor/bhm077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Layer I of the developing cortex contains a dense GABAergic fiber plexus. These fibers provide excitatory inputs to Cajal-Retzius (CR) cells, the early born neurons in layer I. CR cells possess an extensive axonal projection and form synaptic contacts with excitatory, presumably pyramidal, neurons before birth. Interestingly, activity of CR cells declines during the first postnatal week, but mechanism(s) underlying this phenomenon is not yet known. Here we recorded inhibitory postsynaptic currents (IPSCs) in CR cells at postnatal day (P) 1-2 and P5-7. Blockade of adenosine A(1) receptors (A(1)Rs) increased the amplitude of evoked IPSCs (eIPSCs) and decreased paired-pulse ratio at P5-7 but not at P1-2. A(1)R activation decreased the mean eIPSC amplitude at P5-7, but failed to affect eIPSCs at P1-2. Ecto-adenosine triphosphatase (ATPase) inhibition completely abolished the A(1)R-mediated effects suggesting that extracellular ATP is the main source of adenosine. Because A(1)R blockade did not affect the median miniature IPSC amplitude, our results demonstrate that adenosine reduces gamma-aminiobutyric acid (GABA) release probability via presynaptic A(1)Rs at P5-7. As neuronal activity in layer I can depolarize pyramidal neurons influencing thereby glutamatergic synaptogenesis in the lower cortical layers, postnatal weakening of GABAergic transmission by adenosinergic system might reflect a developmental downregulation of this excitatory drive when glutamatergic synapses are formed.
Collapse
Affiliation(s)
- Knut Kirmse
- Institute of Neurophysiology, Johannes-Mueller-Center of Physiology, Charité-University-Medicine Berlin, Tucholskystr. 2, 10117 Berlin, Germany
| | | | | | | |
Collapse
|
6
|
North RA, Verkhratsky A. Purinergic transmission in the central nervous system. Pflugers Arch 2006; 452:479-85. [PMID: 16688467 DOI: 10.1007/s00424-006-0060-y] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2006] [Accepted: 03/06/2006] [Indexed: 12/31/2022]
Abstract
The adenosine 5'-triphosphate (ATP), discovered in 1929 by Karl Lohman, Cyrus Hartwell Fiske, and Yellagaprada SubbaRow, acts as an important extracellular signaling molecule. In the CNS, ATP can be released from synaptic terminals, either on its own or together with other neurotransmitters. After the release from the presynaptic terminals, ATP binds to a plethora of ionotropic and metabotropic receptors, which mediate its action as an excitatory neurotransmitter. Furthermore, ATP also acts as an important mediator in neuronal-glial communications because glial cells are endowed with numerous ATP receptors, which trigger Ca(2+) signaling events and membrane currents in both macro and microglia. In addition, ATP can be released from astroglial cells, thereby acting as a mediator of glial-glial and glial-neuronal signaling.
Collapse
Affiliation(s)
- R Alan North
- Faculty of Life Sciences, The University of Manchester, 1.124 Stopford Building, Oxford Road, Manchester, M13 9PT, UK
| | | |
Collapse
|
7
|
Pankratov Y, Lalo U, Verkhratsky A, North RA. Vesicular release of ATP at central synapses. Pflugers Arch 2006; 452:589-97. [PMID: 16639550 DOI: 10.1007/s00424-006-0061-x] [Citation(s) in RCA: 230] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2006] [Accepted: 03/06/2006] [Indexed: 12/21/2022]
Abstract
Adenosine triphosphate (ATP) acts as a fast excitatory transmitter in several regions of the central nervous system (CNS) including the medial habenula, dorsal horn, locus coeruleus, hippocampus, and somatosensory cortex. Postsynaptic actions of ATP are mediated through an extended family of P2X receptors, widely expressed throughout the CNS. ATP is released via several pathways, including exocytosis from presynaptic terminals and diffusion through large transmembrane pores (e.g., hemichannels, P2X(7) receptors, or volume-sensitive chloride channels) expressed in astroglial membranes. In presynaptic terminals, ATP is accumulated and stored in the synaptic vesicles. In different presynaptic terminals, these vesicles may contain ATP only or ATP and another neurotransmitter [e.g., gamma-amino-butyric acid (GABA) or glutamate]; in the latter case, two transmitters can be coreleased. Here, we discuss the mechanisms of vesicular release of ATP in the CNS and present our own data, which indicate that in central neuronal terminals, ATP is primarily stored and released from distinct pool of vesicles; the release of ATP is not synchronized either with GABA or with glutamate.
Collapse
Affiliation(s)
- Yuri Pankratov
- Faculty of Life Sciences, The University of Manchester, 1.124 Stopford Building, Oxford Road, Manchester, M13 9PT, UK
| | | | | | | |
Collapse
|
8
|
Price GD, Robertson SJ, Edwards FA. Long-term potentiation of glutamatergic synaptic transmission induced by activation of presynaptic P2Y receptors in the rat medial habenula nucleus. Eur J Neurosci 2003; 17:844-50. [PMID: 12603274 DOI: 10.1046/j.1460-9568.2003.02501.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A novel form of long-term potentiation of glutamatergic synaptic transmission is described in the rat medial habenula nucleus. It occurs when uridine 5'-triphosphate is bath applied at low micromolar concentrations and is prevented by Reactive Blue 2, suggesting that it is mediated by P2Y4 receptors. Uridine 5'-diphosphate can also cause such a Reactive Blue 2-sensitive potentiation, but at higher concentrations (200 microm), suggesting that this might also be an effect on the relatively uridine 5'-diphosphate-insensitive P2Y4 receptor. The potentiation is due to an increase in presynaptic release probability. It requires neither depolarization nor calcium influx postsynaptically and is thus probably non-Hebbian. When potentiation due to low concentrations of uridine 5'-triphosphate is inhibited in the presence of Reactive Blue 2, uridine 5'-triphosphate causes instead a significant inhibition of glutamate release. We suggest that this inhibition may be mediated by a Reactive Blue 2-insensitive P2Y2-like receptor. At higher concentrations of uridine 5'-triphosphate (200 micro m), the inhibitory effect dominates such that even in the absence of Reactive Blue 2 no potentiation is seen.
Collapse
Affiliation(s)
- Gareth D Price
- Department of Physiology, University College London, Gower St, London WC1E 6BT, UK
| | | | | |
Collapse
|
9
|
|
10
|
Forrester T. A Purine Signal for Functional Hyperemia in Skeletal and Cardiac Muscle. CURRENT TOPICS IN MEMBRANES 2003. [DOI: 10.1016/s1063-5823(03)01009-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
11
|
|
12
|
Tauc L. Quantal neurotransmitter release: Vesicular or not vesicular? NEUROPHYSIOLOGY+ 1997. [DOI: 10.1007/bf02461232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
13
|
Zimmermann H. Biochemistry, localization and functional roles of ecto-nucleotidases in the nervous system. Prog Neurobiol 1996; 49:589-618. [PMID: 8912394 DOI: 10.1016/0301-0082(96)00026-3] [Citation(s) in RCA: 351] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Nucleotides such as ATP, ADP, UTP or the diadenosine polyphosphates and possibly even NAD+ are extracellular signaling substances in the brain and in other tissues. Enzymes located on the cell surface catalyze the hydrolysis of these compounds and thus limit their spatio-temporal activity. As a final hydrolysis product they generate the nucleoside and phosphate. The paper discusses the biochemical properties, cellular localization and functional properties of surface-located enzymes that hydrolyse nucleotides released from nervous tissue. This is preceded by a brief discussion of nucleotide receptors, cellular storage and mechanisms of nucleotide release. In nervous tissue nucleoside 5'-triphosphates are hydrolysed by ecto-ATP-diphosphohydrolase and possibly in addition also by ecto-nucleoside triphosphatase and ecto-nucleoside diphosphatase. The molecular identity of the ATP-diphosphohydrolase has now been revealed. The hydrolysis of nucleoside 5'-monophosphates is catalysed by 5'-nucleotidase whose biochemical properties and molecular structure have been studied in detail. Little is known about the molecular properties of the diadenosine polyphosphatases. Surface located enzymes for the extracellular hydrolysis of NAD+ and also ecto-protein kinases are discussed briefly. The cellular localization of the ecto-nucleotidases is only partly defined. Whereas in adult mammalian brain activity for hydrolysis of ATP and ADP may be associated with nerve cells or glial cells 5'-nucleotidase appears to have a preferential glial allocation in the adult mammal. The extracellular hydrolysis of the nucleotides is of functional importance not only during synaptic transmission where it functions in signal elimination. It plays a crucial role also for the survival and differentiation of neural cells in vitro and presumably during neuronal development in vivo.
Collapse
Affiliation(s)
- H Zimmermann
- Biozentrum der J.W Goethe-Universität, Frankfurt am Main, Germany
| |
Collapse
|
14
|
Salgado AH, Gomez MV, Romano-Silva MA, Prado MA. Effect of vesamicol on the release of ATP from cortical synaptosomes. Neurosci Lett 1996; 204:37-40. [PMID: 8929972 DOI: 10.1016/0304-3940(96)12310-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The aim of the present experiments was to test whether vesamicol alters the evoked release of ATP from nerve terminals. Continuous or cumulative release of ATP evoked by 33 mM KC1 from rat cerebrocortical synaptosomes was largely calcium-dependent. Vesamicol interfered with release of ATP from synaptosomes depolarized with KCl (33 mM) in a dose-dependent and stereoselective way. The (-)-vesamicol decreased the output of ATP in doses much lower than (+)-vesamicol. The release of the major excitatory neurotransmitter glutamate from depolarized nerve endings was not impaired by vesamicol. We suggest that vesamicol may alter the release of ATP specifically, probably by interacting with a protein similar to the vesamicol receptor found in cholinergic synaptic vesicles.
Collapse
Affiliation(s)
- A H Salgado
- Departamento de Farmacologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | | |
Collapse
|
15
|
Chapter 2 Purines. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s1569-2582(96)80089-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
16
|
Higgins MJ, Hosseinzadeh H, MacGregor DG, Ogilvy H, Stone TW. Release and actions of adenosine in the central nervous system. PHARMACY WORLD & SCIENCE : PWS 1994; 16:62-8. [PMID: 8032343 DOI: 10.1007/bf01880657] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Adenosine is released from active neurons into the extracellular fluid at a concentration of about 1 mumol/l. Neither the precise cellular origin nor the biochemical form of release has been firmly established, though the nucleotide is probably released partly directly, as a result of raised intracellular levels, and partly as nucleotides, which are subsequently hydrolysed. Once in the extracellular medium, adenosine markedly inhibits the release of excitatory neurotransmitters and modulatory peptides and has direct inhibitory effects on postsynaptic excitability via A1 receptors. A population of A2 receptors may mediate depolarization and enhanced transmitter release. Adenosine also modulates neuronal sensitivity to acetylcholine and catecholamines, all these effects probably contributing to the behavioural changes observed in conscious animals. As a result of their many actions, adenosine analogues are being intensively investigated for use as anticonvulsant, anxiolytic, and neuroprotective agents.
Collapse
Affiliation(s)
- M J Higgins
- Department of Pharmacology, University of Glasgow, Scotland
| | | | | | | | | |
Collapse
|
17
|
Marsal J, Egea G, Solsona C, Rabasseda X, Blasi J. Botulinum toxin type A blocks the morphological changes induced by chemical stimulation on the presynaptic membrane of Torpedo synaptosomes. Proc Natl Acad Sci U S A 1989; 86:372-6. [PMID: 2463625 PMCID: PMC286467 DOI: 10.1073/pnas.86.1.372] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The action of botulinum neurotoxin on acetylcholine release, and on the structural changes at the presynaptic membrane associated with the transmitter release, was studied by using a subcellular fraction of cholinergic nerve terminals (synaptosomes) isolated from the Torpedo electric organ. Acetylcholine and ATP release were continuously monitored by chemiluminescent methods. To catch the membrane morphological changes, the quick-freezing method was applied. Our results show that botulinum neurotoxin inhibits the release of acetylcholine from these isolated nerve terminals in a dose-dependent manner, whereas ATP release is not affected. The maximal inhibition (70%) is achieved at neurotoxin concentrations as low as 125 pM with an incubation time of 6 min. This effect is not linked to an alteration of the integrity of the synaptosomes since, after poisoning by botulinum neurotoxin type A, they show a nonmodified occluded lactate dehydrogenase activity. Moreover, membrane potential is not altered by the toxin with respect to the control, either in resting condition or after potassium depolarization. In addition to acetylcholine release inhibition, botulinum neurotoxin blocks the rearrangement of the presynaptic intramembrane particles induced by potassium stimulation. The action of botulinum neurotoxin suggests that the intramembrane particle rearrangement is related to the acetylcholine secretion induced by potassium stimulation in synaptosomes isolated from the electric organ of Torpedo marmorata.
Collapse
Affiliation(s)
- J Marsal
- Departament de Biologia Cellular i Anatomia Patològica, Facultat de Medicina, Hospital de Bellvitge, Universitat de Barcelona, Spain
| | | | | | | | | |
Collapse
|
18
|
Tolkovsky AM, Suidan HS. Adenosine 5'-triphosphate synthesis and metabolism localized in neurites of cultured sympathetic neurons. Neuroscience 1987; 23:1133-42. [PMID: 3437992 DOI: 10.1016/0306-4522(87)90187-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Adenosine triphosphate synthesis and metabolism in cultured sympathetic neurons was studied after the incorporation of [2-3H]adenine into intact or microdissected neurites to determine whether ATP is provided locally during neurite outgrowth, when and where it is synthesized and how its levels are regulated at rest and following depolarization. Neurites maintained an independent capability for synthesis of ATP at any stage of growth: [3H]ATP levels increased in neurites in direct proportion to neurite length and equivalent amounts of [3H]ATP were synthesized by intact neurites, by neurites separated from cell bodies or by neurites further segmented into sections. Thus, metabolic labelling of cultured neurons with [3H]adenine provides a simple method to measure relative neurite outgrowth. Neurite ATP was maintained mainly by respiration but also by glycolysis and [3H]ATP levels were stable for at least 14 h after adenine withdrawal when cells were at rest. Depolarization overcame respiratory control, causing a quantitative conversion of ATP to adenosine monophosphate (AMP) and inosine monophosphate (IMP) and the release of nucleosides (adenosine and inosine) and nucleotides [adenosine diphosphate (ADP) and adenosine monophosphate (AMP)]. Release of nucleosides, but not of nucleotides or [3H]noradrenaline, was enhanced by NaN3 or 2-deoxyglucose under nondepolarizing conditions and was prevented by the adenosine transport inhibitor p-nitrobenzyl-6-thioinosine. It is concluded that neurites can use local mechanisms for ATP synthesis that do not depend on a functional connection to the cell body. Any metabolic stress which causes ATP breakdown causes these cells to express a transient purinergic phenotype involving release of adenosine and inosine by facilitated diffusion. To promote the release of purine nucleotides, however, more specific stimuli are required.
Collapse
Affiliation(s)
- A M Tolkovsky
- Department of Biochemistry, Cambridge University, U.K
| | | |
Collapse
|
19
|
Abstract
Cholinergic nerve terminals were affinity purified from rat caudate nucleus. On stimulation with both 22.6 mM KCl and 50 microM veratridine, ATP was released in a Ca2+-dependent manner. The molar ratio of released acetylcholine to ATP (9:1) was closer to that found in isolated cholinergic vesicles (7:1) than whole terminals (3:1). Extracellular [14C]ATP was rapidly metabolized by these terminals to adenosine and inosine via ectonucleotidases. The terminals had a saturable, high-affinity uptake mechanism for adenosine (Km = 16.6 microM). Veratridine stimulation also caused the Ca2+-dependent release of nucleosides in a dipyridamole-sensitive manner. Both theophylline treatment and inhibition of extracellular ATP breakdown resulted in increased ATP and nucleoside release. Extracellular adenosine was shown to inhibit acetylcholine release, probably via the A1 receptor. The role of extracellular purines at the cholinergic nerve terminal is discussed.
Collapse
|
20
|
Marsal J, Solsona C, Rabasseda X, Blasi J, Casanova A. Depolarization-induced release of ATP from cholinergic synaptosomes is not blocked by botulinum toxin type A. Neurochem Int 1987; 10:295-302. [DOI: 10.1016/0197-0186(87)90103-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/1986] [Accepted: 10/13/1986] [Indexed: 10/27/2022]
|
21
|
Knipper M, Breer H. Regulation of the high affinity choline transport in locust synaptosomes by adenosine triphosphate. Neurosci Lett 1986; 72:347-51. [PMID: 3822238 DOI: 10.1016/0304-3940(86)90539-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effect of various nucleotides on the high affinity choline accumulation by synaptosomes from locusts has been studied. Extracellular adenosine triphosphate (ATP) was found to inhibit the transport of choline, whereas the accumulation of gamma-aminobutyric acid was not affected. The ATP-effect could not be mimicked by other purine derivatives, and seems not be mediated by purinergic receptors, but rather hydrolysis of the phosphate appears to be essential.
Collapse
|
22
|
|
23
|
Quintana J. Adenosine and related nucleotides alter calcium uptake in depolarized synaptosomes of torpedo electric organ. J Neural Transm (Vienna) 1985; 64:271-84. [PMID: 4086992 DOI: 10.1007/bf01256472] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Calcium has been shown to enter cholinergic synaptosomes transiently during potassium-induced depolarization, in which ACh and ATP are released together. Because junctional ATP is rapidly hydrolyzed by extracellular ATPases, I studied and compared the roles of ATP, ADP, AMP, and adenosine (Ade) on the control of calcium uptake during depolarization. Pure cholinergic synaptosomes of Torpedo fish electric organ were depolarized by high potassium concentrations and the amount of calcium uptake was then measured in the presence of equal concentrations of Ade and its related nucleotides. Calcium uptake was more inhibited when the nucleotide was less phosphorylated. Thus, Ade was the greatest inhibitor. Because Ade is quickly and actively taken up from the extracellular medium by synaptosomes and converted intracellularly to ATP, I also measured the capacity of Ade, after its initial inhibitory action, to reactivate the calcium uptake. After a short preincubation with Ade, the later uptake of calcium was enhanced. The combined results support a complete role of adenosine and related nucleotides in the control of calcium movement across the presynaptic membrane.
Collapse
|
24
|
Burnstock G. Nervous control of smooth muscle by transmitters, cotransmitters and modulators. EXPERIENTIA 1985; 41:869-74. [PMID: 2861107 DOI: 10.1007/bf01970003] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
25
|
Abstract
The effects of ATP gamma S, a slowly hydrolyzable analogue of ATP, were investigated in the preparation of synaptosomes isolated from rat cerebral cortex. It was found that addition of [35S]ATP gamma S resulted in substantial magnesium-dependent incorporation of 35S into synaptosomal proteins which was prevented completely by ATP. The most prominently labeled polypeptides were those with apparent molecular weights of 100,000; 84,000; 74,000; 62,000; 55,000; 48,000; and 41,000. The rate and extent of thiophosphorylation were unaffected by addition of cAMP, veratridine or sodium fluoride. ATP gamma S at 50-100 microM had no effect on either uptake or release of gamma-aminobutyric acid (GABA) and dopamine; at a concentration of 1 mM it inhibited incorporation of dopamine by about 20%. This inhibition was also seen with 1 mM GTP, beta, gamma-methylene-adenosine 5'-triphosphate and adenylylimidodiphosphate, which suggests that the nucleotide triphosphates themselves, and not membrane protein phosphorylation, were responsible for the effect observed. It is concluded that ATP gamma S is an effective tool for studying the possible role of ATP released in synaptic transmission. The results obtained thus far suggest that neither extrasynaptosomal ATP nor phosphorylation of external proteins of the presynaptic membrane is sufficient for modulation of neurotransmitter uptake or release. They may, however, play a role in combination with other conditions.
Collapse
|
26
|
Abstract
Recent studies have described a transmitter-like release of ATP in brain. Once released, extraneuronal ATP is rapidly metabolized to adenosine by ecto-ATPase and nucleotidase. Adenosine, through actions at specific receptors, inhibits neuronal firing in the brain. ATP shares these inhibitory actions, presumably by forming adenosine extraneuronally. Caffeine and theophylline probably exert CNS stimulation by antagonizing adenosine's inhibitory actions in the brain. Extracellular ATP occasionally excites quiescent neurons in the cortex. A possible role for ATP as a sensory neurotransmitter is suggested by its excitatory actions on a subpopulation of dorsal horn cells. ATP release has also been described from sensory nerves in the periphery, motor nerves, nerves of the myenteric plexus, bladder, vas deferens, and from adrenal chromaffin cells and platelets. The possibility that ATP might function as a transmitter, co-transmitter or modulator in the peripheral nervous system is discussed.
Collapse
|
27
|
Potter PE, White TD. Lack of effect of 6-hydroxydopamine pretreatment on depolarization-induced release of ATP fron rat brain synaptosomes. Eur J Pharmacol 1982; 80:143-7. [PMID: 7095000 DOI: 10.1016/0014-2999(82)90191-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Pretreatment of rats with intraventricular 6-hydroxydopamine produced considerable destruction of noradrenergic and dopaminergic nerve terminals as indicated by depletions in synaptosomal catecholamine contents. However, 6-hydroxydopamine pretreatment did not result in diminished release of ATP during depolarization of synaptosomes with either elevated extracellular K+ or veratridine. These findings suggest that most of the ATP released during the depolarization of rat brain synaptosomal preparations is not co-released with noradrenaline or dopamine but must originate from other sources.
Collapse
|
28
|
Morel N, Meunier FM. Simultaneous release of acetylcholine and ATP from stimulated cholinergic synaptosomes. J Neurochem 1981; 36:1766-73. [PMID: 7241136 DOI: 10.1111/j.1471-4159.1981.tb00429.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The release of acetylcholine (ACh) and ATP from pure cholinergic synaptosomes isolated from the electric organ of Torpedo was studied in the same perfused sample. A presynaptic ATP release was demonstrated either by depolarization with KCl or after the action of a venom extracted from the annelid Glycera convoluta (GV). The release of ATP exhibited similar kinetics to that of ACh release and was therefore probably closely related to the latter. The ACh/ATP ratio in perfusates after KCl depolarization was 45; this was much higher than the ACh/ATP ratio in cholinergic synaptic vesicles, which was 5. The ACh/ATP ratio released after the action of GV was also higher than that of synaptic vesicles. These differences are discussed. The stoichiometry of that of synaptic vesicles. These differences are discussed. The stoichiometry of ACh and ATP release is not consistent with the view that the whole synaptic vesicle content is released by exocytosis after KCl depolarization, as is the case for chromaffin cells in the adrenal medulla.
Collapse
|
29
|
|
30
|
Potter P, White TD. Release of adenosine 5'-triphosphate from synaptosomes from different regions of rat brain. Neuroscience 1980; 5:1351-6. [PMID: 7402474 DOI: 10.1016/0306-4522(80)90207-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|