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Hattori T, Tamamura Y, Tokunaga K, Sakurai T, Kato R, Sawada K. Two-dimensional microchemical observation of mast cell biogenic amine release as monitored by a 128 × 128 array-type charge-coupled device ion image sensor. Anal Chem 2014; 86:4196-201. [PMID: 24731060 DOI: 10.1021/ac403657w] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Available array-type, chemical-sensing image sensors generally only provide on/off responses to the sensed chemical and produce qualitative information. Therefore, there is a need for an array sensor design that can detect chemical concentration changes to produce quantitative, event-sensitive information. In this study, a 128 × 128 array-type image sensor was modified and applied to imaging of biogenic amines released from stimulated rat mast cells, providing recordable responses of the time course of their release and diffusion. The imaging tool was manufactured by an integrated circuit process, including complementary metal oxide semiconductor and charge-coupled device technology. It was fitted with an amine-sensitive membrane prepared from plasticized poly(vinyl chloride) including a hydrophobic anion, which allowed the sensor to detect amines, such as histamine and serotonin, in Tyrode's solution. As mast cells were larger in diameter than the pixel hollows, some pixels monitored amines released from single cells. The image from the array responses yielded sequential snapshots at a practical frame speed that followed amine concentration changes over time, after mast cell amine release was synchronized by chemical stimulation. This sensor was shown to be sensitive to amine release at very low stimulus concentrations and was able to detect localized spots of high amine release. The entire time course of the amine release was recorded, including maximum concentration at 4-6 s and signal disappearance at 30 s after stimulation. With further development, this sensor will increase opportunities to study a variety of biological systems, including neuronal chemical processes.
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Affiliation(s)
- Toshiaki Hattori
- Department of Electrical and Electronic Information Engineering, ‡Department of Environmental and Life Sciences, §Electronics-Inspired Interdisciplinary Research Institute, and ∥Cooperative Research Facility Center, Toyohashi University of Technology , Toyohashi 441-8580, Japan
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Kim J, Ohki A, Ueki R, Ishizuka T, Shimotashiro T, Maeda S. Cesium-ion selective electrodes based on calix[4]arene dibenzocrown ethers. Talanta 2012; 48:705-10. [PMID: 18967511 DOI: 10.1016/s0039-9140(98)00291-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/1998] [Revised: 08/26/1998] [Accepted: 09/02/1998] [Indexed: 11/18/2022]
Abstract
Four calix[4]arene dibenzocrown ether compounds have been prepared and evaluated as Cs(+)-selective ligands in solvent polymeric membrane electrodes. The ionophores include 25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-6 1, 25,27-bis(1-alkyloxy)calix[4]arene dibenzocrown-7s 2 and 3, and 25,27-bis(1-propyloxy)calix[4]arene dibenzocrown-8 4. For an ion-selective electrode (ISE) based on 1, the linear response concentration range is 1x10(-1) to 1x10(-6) M of Cs(+). Potentiometric selectivities of ISEs based on 1-4 for Cs(+) over other alkali metal cations, alkaline earth metal cations, and NH(4)(+) have been assessed. For 1-ISE, a remarkably high Cs(+)/Na(+) selectivity was observed, the selectivity coefficient (K(Cs,Na)(Pot)) being ca. 10(-5). As the size of crown ether ring is enlarged from crown-6 (1) to crown-7 (2 and 3) to crown-8 (4), the Cs(+) selectivity over other alkali metal cations, such as Na(+) and K(+), is reduced successively. Effects of membrane composition and pH in the aqueous solution upon the electrode properties are also discussed.
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Affiliation(s)
- J Kim
- Department of Chemistry, Konyang University, Nonsan, 320-800, South Korea
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3
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Individual extraction constants of some divalent metal cations in the two-phase water–nitrobenzene system. J Radioanal Nucl Chem 2010. [DOI: 10.1007/s10967-010-0598-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Wuhrmann HR, Morf WE, Simon W. Modellberechnung der EMK und der Ionenselektivität von Membranelektroden-Messketten. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19730560320] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Mikhelson KM, Bobacka J, Ivaska A, Lewenstam A, Bochenska M. Selectivity of lithium electrodes: correlation with ion-lonophore complex stability constants and with interfacial exchange current densities. Anal Chem 2002; 74:518-27. [PMID: 11838669 DOI: 10.1021/ac0155660] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lithium-selective electrodes with solvent polymeric membranes based on two different dicyclohexylamide neutral ionophores are studied systematically. The selectivity of lithium response is studied by means of the ordinary potentiometric experiments. Stability constants of lithium, sodium, and potassium ions with the neutral ionophores are measured by means of the segmented sandwich membrane method. Charge transfer through the membrane bulk and across the membrane/solution interface is studied by means of electrochemical impedance spectroscopy. Well-resolved Faradaic impedance semicircles are obtained, allowing calculation of exchange current densities for lithium, sodium, and potassium. It is clearly demonstrated that the potentiometric selectivity coefficients correlate well with thermodynamic equilibrium parameters. The correlation with exchange current densities also exists, although it is low, and seems rather qualitative than quantitative. The results are treated in favor of equilibrium at the membrane/solution interface. It is also concluded (tentatively) that the kinetic description is equivalent to the equilibrium one, giving evidence that ion-ionophore complexes form directly at the interface.
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MASADOME T, IMATO T, WAKIDA SI, HIGASHI K, ASANO Y. Relationship between the Hydrophobicity of Cations and the Cationic Response of a Plasticized Poly(vinyl chloride) Membrane Electrode with no Added Ion-Exchanger. ANAL SCI 2000. [DOI: 10.2116/analsci.16.383] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takashi MASADOME
- Department of Chemical Science and Engineering, Ariake National College of Technology
| | - Toshihiko IMATO
- Department of Chemical Systems and Engineering, Graduate School of Engineering, Kyushu University
| | - Shin-ichi WAKIDA
- Department of Energy and the Environment, Osaka National Research Institute, Agency of Industrial Science and Technology, Ministry of International Trade and Industry
| | - Kunishige HIGASHI
- Department of Energy and the Environment, Osaka National Research Institute, Agency of Industrial Science and Technology, Ministry of International Trade and Industry
| | - Yasukazu ASANO
- Laboratory of Chemistry, Department of General Education, Ariake National College of Technology
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Jadhav S, Bakker E. Voltammetric and amperometric transduction for solvent polymeric membrane ion sensors. Anal Chem 1999; 71:3657-64. [PMID: 10489520 DOI: 10.1021/ac990195x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This paper describes basic response features of solvent polymeric membrane ion sensors with voltammetric and amperometric transduction. The model systems used here contain no ionophore for simplicity reasons. Reasonable simplifications of the theory are introduced that allow one to understand the response mechanism in view of a practical application of these sensors. It is shown that ion-sensing membranes preferentially contain no ion-exchanger properties in order to function optimally in a voltammetric mode. As with the systems studied by Kihara, both liquid-polymer interfaces of the membrane are preferably polarizable. Specifically, they contain the highly lipophilic electrolyte tetradodecylammonium tetrakis(4-chlorophenyl)borate (ETH 500) in the membrane to improve lifetime, increase the magnitude of the potential window, and prohibit exchange reactions with sample ions. An ohmic behavior that is associated with an assisted electrolyte-transfer process is observed only above a threshold potential which can be quantitatively predicted by theory. The threshold potential depends on the nature and activity of sample anions and cations in the sample and inner filling solution of the membrane electrode. Within the experimental conditions discussed in this paper, these sensors seem to measure sample ion activities, not concentrations, since the rate-limiting step is the diffusion of extracted ions away from the interface into the membrane bulk. Similarly, no effect of sample stirring on the measured current is observed. This contrasts to work done on liquid-liquid electrolyte-transfer reactions, where large diffusion coefficients in the organic phase often lead to substantial sample depletion effects. The detection of anions and cations with the same membrane is demonstrated in a cyclic voltammetric mode. Direct continuous detection of one type of anion is accomplished by pulsed amperometry to ensure a rapid, repetitive renewal of the membrane composition between measurements.
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Affiliation(s)
- S Jadhav
- Department of Chemistry, Aubuur University, Alabama 36849, USA
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Katsu T, Mori Y, Furuno K, Gomita Y. Mexiletine-sensitive membrane electrode for medical application. J Pharm Biomed Anal 1999; 19:585-93. [PMID: 10704124 DOI: 10.1016/s0731-7085(98)00260-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Response characteristics of mexiletine-sensitive membrane electrodes based on crown ether and ion-exchanger were examined in a physiological saline in order to find an electrode suitable for determining concentrations of this drug under physiological conditions. Among various crown ethers screened, 4',4"(5")-di-tert-butyldicyclohexano-18-crown6 showed the highest sensitivity to mexiletine in physiological saline containing 0.15 M NaCl and 5 mM 4-(2-hydroxyethyl)-2-piperazineethanesulfonic acid (Hepes) NaOH (pH 7.4). However, the detection limit of 30 microM was 10 times higher than that of 3 microM observed with the electrode based on an ion-exchanger, sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propyl)phenyl]borate. Having high selectivity against inorganic cations such as Na+ or K+, the electrode using the ion-exchanger enabled us to determine the level of mexiletine in saliva, the monitoring of which is quite effective for controlling the dose of this drug noninvasively. The mexiletine concentrations determined with the mexiletine electrode compared favourably with those determined by high-performance liquid chromatography which requires an additional procedure to extract mexiletine from saliva.
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Affiliation(s)
- T Katsu
- Faculty of Pharmaceutical Sciences, Okayama University, Tsushima-naka, Japan.
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Abstract
Therapeutic lithium levels in the treatment of manic depressive psychosis must be maintained in the range of 0.5-1.5 mM in the blood, which also contains 140 mM sodium. This paper reviews spectrophotometric, fluorometric, and ion-selective electrode (ISE) reagents and methods for achieving high lithium selectivity over sodium and their use in blood lithium measurement. These include aromatic organic reagents, crown ethers and amide ionophores. Crown ethers and cryptands provide the best lithium selectivity. A chromophoric small-cavity cryptand phenol exhibits greater than 4000:1 selectivity due to rigid configuration of a well preorganized binding site for lithium complexation. It is water soluble, making it easy to apply for blood analysis. Crown ethers with bulky groups inhibit formation of the 2:1 crown:sodium complex, while allowing formation of the 1:1 lithium complex. A PTM 14-crown-4 having a bulky pinane and subunits at the ethano bridge exhibits at least 10,000:1 selectivity for lithium in a flow-through optical sensor probe. Bulky crown ethers used in PVC membrane ion-selective electrodes exhibit lithium selectivities of 1-2000:1. Methods of evaluating selectivities are discussed, along with the correlation of solvent extraction of crown ether complexes and solvent membrane ISE selectivities.
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Affiliation(s)
- G D Christian
- Department of Chemistry, University of Washington, Seattle 98195-1700, USA.
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Bloms-Funke P, Madeja M, Musshoff U, Speckmann EJ. Effects of pentylenetetrazol on GABA receptors expressed in oocytes of Xenopus laevis: extra- and intracellular sites of action. Neurosci Lett 1996; 205:115-8. [PMID: 8907330 DOI: 10.1016/0304-3940(96)12391-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The convulsive agent pentylenetetrazol (PTZ) antagonized gamma-aminobutyric acid (GABA)-induced membrane currents on RNA-injected Xenopus oocytes with both extra- and intracellular applications. With extracellular administration PTZ enters the cell within a few minutes and reaches concentrations in the millimolar range. The permeability of the plasma membrane makes it possible for systemically applied PTZ to elicit its effect on the GABA-induced currents via extra- as well as intracellular sites of action.
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Affiliation(s)
- P Bloms-Funke
- Institute fur Physiologie der Westfalischen Wilhelms-Universitat Munster, Germany
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12
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Bakker E, Pretsch E. Lipophilicity of tetraphenylborate derivatives as anionic sites in neutral carrier-based solvent polymeric membranes and lifetime of corresponding ion-selective electrochemical and optical sensors. Anal Chim Acta 1995. [DOI: 10.1016/0003-2670(95)00077-d] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Coşofre VV, Buck RP. Recent Advances in Pharmaceutical Analysis with Potentiometric Membrane Sensors. Crit Rev Anal Chem 1993. [DOI: 10.1080/10408349308048818] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Lundbaek JA, Hansen AJ. Brain interstitial volume fraction and tortuosity in anoxia. Evaluation of the ion-selective micro-electrode method. ACTA PHYSIOLOGICA SCANDINAVICA 1992; 146:473-84. [PMID: 1492565 DOI: 10.1111/j.1748-1716.1992.tb09449.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The micro-electrode method for determination of interstitial volume fraction (alpha) (Nicholson & Phillips 1981), was evaluated. The extracellular marker, tetramethylammonium+, is iontophoretically ejected from a micropipette and the change in concentration measured at a distance by an ion-sensitive micro-electrode and fitted to a diffusion equation. We used suspensions of human red blood cells as a model system and found that the values of alpha determined by this method and by haematocrit measurement were linearly correlated (r = 0.94) and not significantly different. The micro-electrode method was used to characterize the interstitial space in rat brain cortex during normal conditions and during arrest of blood flow supply. Transport of solutes in interstitial space is governed by two characteristics, the interstitial volume fraction and the tortuosity factor. During control conditions, the interstitial volume fraction was 0.18 +/- 0.02 (mean +/- SEM), whereas it decreased to 0.07 +/- 0.01 in ischaemia. The tortuosity factor was 1.40 +/- 0.05 in controls and increased to 1.63 +/- 0.09 during ischaemia. Our measurements support the validity of the micro-electrode method (Nicholson & Phillips 1981) and demonstrate that arrest of blood supply changes interstitial diffusional characteristics of brain cortex mainly by diminishing the size of the interstitial diffusional space.
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Affiliation(s)
- J A Lundbaek
- Department of General Physiology and Biophysics, Panum Institute, University of Copenhagen, Denmark
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15
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Šustáček V, Šenkýř J. Selectivity coefficients of univalent cations for liquid ion-exchange membrane electrodes based on nitrobenzene. J Electroanal Chem (Lausanne) 1990. [DOI: 10.1016/0022-0728(90)85164-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Wang CN, Metcalfe LD, Donkerbroek JJ, Cosijn AHM. Potentiometric titration of long chain quaternary ammonium compounds using sodium tetraphenyl borate. J AM OIL CHEM SOC 1989. [DOI: 10.1007/bf02660757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- C. N. Wang
- Research Laboratory; Akzo Chemicals Inc.; 60525 McCook IL
| | - L. D. Metcalfe
- Research Laboratory; Akzo Chemicals Inc.; 60525 McCook IL
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18
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Coles JA, Schneider-Picard G. Increase in glial intracellular K+ in drone retina caused by photostimulation but not mediated by an increase in extracellular K+. Glia 1989; 2:213-22. [PMID: 2527820 DOI: 10.1002/glia.440020402] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The predominant glial cells of the drone retina (outer pigment cells) respond to an increase in extracellular [K+] (Ko) by a net uptake of K+; thus, they contribute to bringing Ko back toward its baseline value. The authors report herein that there is also a different mechanism by which light stimulation of the retina causes an increase in intracellular free [K+] in the glial cells. In superfused retinal slices, after 5-10 minutes of continuous illumination at physiological intensities, extracellular [K+] often fell back to below its original level in the dark. This fall can be explained by increased activity of the Na/K pump in the photoreceptors and diffusion of K+ down their axons. Despite the absence of raised Ko, K+-selective microelectrodes in glial cells recorded a small increase in intracellular [K+] that was maintained for the duration of the illumination; i.e. a change occurred in the glia that was not mediated by an increase in Ko. The increase in intracellular [K+] is not mediated by illumination of the screening pigment in the glia. Unless the increase is caused by illumination of some other, unknown, pigment in the glia, the results show that some unidentified signal (that is not K+) passes from the photoreceptors to the glia.
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Abstract
The use of ion-selective electrodes and potentiometric techniques in the analysis of drug substances are reviewed. Sensors for potentiometric measurements, potentiometric ion-pair and complex formation-based titrations, titrants, and applications are discussed. Other potentiometric methods used in the analysis of pharmaceuticals are discussed.
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Affiliation(s)
- K Vytras
- Department of Analytical Chemistry, University of Chemical Technology, Pardubice, Czechoslovakia
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Reid KH, Marrannes R, Wauquier A. Effects of temperature and temperature gradients on ion-sensitive microelectrodes. J Neurosci Methods 1988; 25:49-57. [PMID: 3221686 DOI: 10.1016/0165-0270(88)90119-7] [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: 01/04/2023]
Abstract
Ion-sensitive microelectrodes are widely used in studies of mammalian tissues. Often the tissue is maintained at 37 degrees C, some 10-15 degrees C above room temperature. The temperature difference between the room and the preparation was found to be capable of altering the measured ion potential by as much as 10 mV. The change depended on 3 factors: the temperature dependence of the Nernst slope, the temperature dependence of the interference factor, and the thermoelectric potential induced by the temperature difference between the two ends of the ion-exchanger column. Certain combinations of these changes can cancel each other, resulting in spurious but apparently temperature-insensitive readings. The first two factors can produce errors when the temperature of calibration differs from the temperature of the tissue being measured. Serious errors in measurements of ion concentration can also occur, due to all 3 factors, if a temperature gradient exists across the ion exchanger column; this situation can easily occur when recording from exposed mammalian tissues. The use of a short ion-exchanger column will reduce but not eliminate effects due to a temperature gradient.
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Affiliation(s)
- K H Reid
- Department of Neuropharmacology, Janssen Pharmaceutica, Beerse, Belgium
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Reid KH, Marrannes R, Wauquier A. Spreading depression and central nervous system pharmacology. JOURNAL OF PHARMACOLOGICAL METHODS 1988; 19:1-21. [PMID: 2896809 DOI: 10.1016/0160-5402(88)90040-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Spreading depression is a reversible response of brain tissue to a local insult. It has been postulated to be the physiological substrate for the aura phase of classic migraine. The properties and mechanisms of spreading depression were studied in the parietal neocortex of the alfentanil-anesthesized rat, by using a cup electrode that provided close control of the electrical stimulus while allowing specific ion (K+) and potential recordings to be made directly beneath the cathode, the region of origin of the stimulus-induced spreading depression. Cathodal stimulation caused the extracellular K+ concentration to rise, and spreading depressions were observed when this concentration exceeded 8-12 mM in the upper 100-200 microns of cortex. In some experiments extracellular [K+] continued to increase for 5-10 sec after termination of the stimulus, without detectable after-discharge in the potential record, before subsiding. While spreading depression could easily be induced by pressure on the cortex, local damage incidental to opening the dura rarely induced spreading depression. This suggests that a local (1-mm2) neurovascular injury is not likely to induce spreading depression--at least in normal cortex--and so is probably not the source of the spreading depression postulated to generate the aura of classic migraine. Mechanisms of spreading depression, and drugs that influence spreading depression, are reviewed, and possible uses of spreading depression in the pharmacology of the central nervous system are considered.
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Affiliation(s)
- K H Reid
- Department of Physiology, School of Medicine, University of Louisville, Kentucky 40292
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22
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Coles JA. Bias current modifies the selectivity of liquid membrane ion-selective microelectrodes. Pflugers Arch 1988; 411:339-44. [PMID: 3380648 DOI: 10.1007/bf00585125] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A negative bias potential of up to -80 mV applied to the back of a liquid membrane ion-selective microelectrode containing classical "K+" ion-exchanger was found to make it more selective for millimolar concentrations of K+ over micromolar concentrations of choline, tetramethylammonium, tetraethylammonium and 5-hydroxytryptamine. Conversely, positive bias potential increased severalfold the sensitivity to micromolar concentrations of these ions while decreasing the sensitivity to K+. An increase in response amplitude for millimolar changes of ion concentration was also observed in neutral carrier electrodes for Na+, K+ and Ca2+ with negative bias potential. The various ions caused the resistances of the electrodes to change; these resistance changes contributed to the changes in response amplitude, but there were additional, unexplained, factors. The phenomenon was used to test if the signal from a K+ ion-exchanger microelectrode in extracellular space in bee retina was contaminated by substances other than K+.
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Affiliation(s)
- J A Coles
- Université de Genève, Département d'Oto-Neuro-Ophtalmologie, Switzerland
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Katsu T, Kanamitsu M, Hirota T, Fujita Y. Determination of Serotonin Release from Platelets by Using A Serotonin-Selective Membrane Electrode. ANAL LETT 1987. [DOI: 10.1080/00032718708067989] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Verselis V, White RL, Spray DC, Bennett MV. Gap junctional conductance and permeability are linearly related. Science 1986; 234:461-4. [PMID: 3489990 DOI: 10.1126/science.3489990] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The permeability of gap junctions to tetraethylammonium ions was measured in isolated pairs of blastomeres from Rana pipiens L. and compared to the junctional conductance. In this system, the junctional conductance is voltage-dependent and decreases with moderate transjunctional voltage of either sign. The permeability to tetraethylammonium ions was determined by injecting one cell of a pair with tetraethylammonium and monitoring its changing concentration in the prejunctional and postjunctional cells with ion-selective electrodes. Junctional conductance was determined by current-clamp and voltage-clamp techniques. For different cell pairs in which the transjunctional voltage was small and the junctional conductance at its maximum value, the permeability to tetraethylammonium ions was proportional to the junctional conductance. In individual cell pairs, a reduction in the junctional conductance induced by voltage was accompanied by a proportional reduction in the permeability of the gap junction over a wide range. The diameter of the tetraethylammonium ion (8.0 to 8.5 A, unhydrated) is larger than that of the potassium ion (4.6 A, hydrated), the predominant current-carrying species. The proportionality between the permeability to tetraethylammonium ions and the junctional conductance, measured here with exceptionally fine time resolution, indicates that a common gap junctional pathway mediates both electrical and chemical fluxes between cells, and that closure of single gap junction channels by voltage is all or none.
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Hiratani K, Okada T, Sugihara H. Di-n-octyl Phenyl Phosphonate: A Plasticizer of Poly(vinyl chloride) Matrix Membrane Electrodes Behaving As a Li+-selective Agent. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1986. [DOI: 10.1246/bcsj.59.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kakiuchi T, Obi I, Senda M. Tetraalkylammonium Ion-selective Electrodes with Supporting Electrolytes. An Experimental Test of the Theory of Liquid Ion-exchange Membrane Ion-selective Electrodes Based on the Concept of the Mixed Ion-transfer Potential. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1985. [DOI: 10.1246/bcsj.58.1636] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Hundhammer B, Seidlitz H, Becker S, Dhawan S, Solomon T. The dependence of the galvani potential difference between water and nitrobenzene on salt partition. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0368-1874(84)83593-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Walden J, Lehmenkühler A, Speckmann EJ, Witte OW. Continuous measurement of pentylenetetrazol concentration by a liquid ion exchanger microelectrode. J Neurosci Methods 1984; 11:187-92. [PMID: 6492863 DOI: 10.1016/0165-0270(84)90037-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A double-barrelled microelectrode is described, which permits the continuous measurement of the concentration of the epileptogenic agent pentylenetetrazol (PTZ). The electrode is based on the liquid potassium exchanger (Corning No. 477 317) and enables measurements of PTZ concentration in physiological salines down to 1 mM. The electromotive behaviour of the liquid membrane against PTZ cannot directly be described by the Nicolsky-Eisenman formalism. It is suggested that specific interactions of the PTZ molecule with the Corning ligand are involved in the potential generating mechanisms.
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Meier P, Morf W, Läubli M, Simon W. Evaluation of the optimum composition of neutral-carrier membrane electrodes with incorporated cation-exchanger sites. Anal Chim Acta 1984. [DOI: 10.1016/s0003-2670(00)85531-2] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Determination of some pharmaceuticals using simple potentiometric sensors of coated-wire type. Mikrochim Acta 1984. [DOI: 10.1007/bf01204165] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Ion-Selective Electrodes of Extended Linear Range. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/b978-0-08-029692-0.50008-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Davis S, Olejnik O. The determination of free long-chain quaternary ammonium species with an ion-selective electrode based on a cetyltrimethylammonium ion pair. Anal Chim Acta 1981. [DOI: 10.1016/s0003-2670(01)93876-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Vytřas K, Remeš M, Kubešová-Svobodová H. Coated-wire organic ion-selective electrodes in titrations based on ion-pair formation. Anal Chim Acta 1981. [DOI: 10.1016/s0003-2670(01)83901-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Erne D, Stojanac N, Ammann D, Hofstetter P, Pretsch E, Simon W. Lipophilic Di- and Triamides as Ionophores for Alkaline Earth Metal Cations. Helv Chim Acta 1980. [DOI: 10.1002/hlca.19800630816] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Hansen AJ, Olsen CE. Brain extracellular space during spreading depression and ischemia. ACTA PHYSIOLOGICA SCANDINAVICA 1980; 108:355-65. [PMID: 7415848 DOI: 10.1111/j.1748-1716.1980.tb06544.x] [Citation(s) in RCA: 242] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The change of extracellular space volume of rat brain cortex during ischemia and cortical spreading depression, CSD (Leão 1944) was evaluated by a new method. The cortical surface was irrigated with isotonic CSF containing the extracellular markers 50 mM cholin or 50 mM trimethyltris(hydroxymethyl)methyl ammonium ion (N-TRIS), and their extracellular concentrations were monitored by ion-selective microelectrodes. When steady-state for the concentration of these markers was attained, CSD evoked a reversible increase of the concentration of the markers, indicating shrinkage of the interstitial volume of distribution. During ischemia an initial slow rate of concentration increase was observed, followed a few minutes later by a rapid increase concomitant with the sharp rise in extracellular potassium concentration. During CSD and ischemia, the maximal increases of choline and N-TRIS concentration reflected a shrinkage of the extracellular space amounting to about 50% of the initial volume.
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Microelectrode for potassium ions based on a neutral carrier and comparison of its characteristics with a cation exchanger sensor. Anal Chim Acta 1976. [DOI: 10.1016/s0003-2670(01)83013-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Dewolfs R, Broddin G, Clysters H, Deelstra H. Comparison of two electrodes for the determination of ammonia and nitrogen compounds. ACTA ACUST UNITED AC 1975. [DOI: 10.1007/bf00437764] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Morf WE, Kahr G, Simon W. Reduction of the Anion Interference in Neutral Carrier Liquid-Membrane Electrodes Responsive to Cations. ANAL LETT 1974. [DOI: 10.1080/00032717408059014] [Citation(s) in RCA: 80] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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