Neutral carrier based hydrogen ion selective microelectrode for extra- and intracellular studies

Ammann, D.; Lanter, F.; Steiner, R. A.; Schulthess, Peter; Shijo, Yoshio; Simon, W.

doi:10.1021/ac00237a031

Cited by 384 publications

(201 citation statements)

References 23 publications

Supporting

Mentioning

192

Contrasting

Unclassified

Order By: Relevance

“…The electrodes were constructed as described in two recent communications (Kraig et aI., 1983;Mutch and Hansen, 1984). Following silanization, the tip of the pH barrel was filled with the pH "cocktail" developed by Ammann et al (1981), and the barrel was back-filled with a phosphate buffer (pH 6.5). The reference barrel con tained 0.16 M KCI.…”

Section: Experimental Seriesmentioning

confidence: 99%

Extra- and Intracellular pH in the Brain during Seizures and in the Recovery Period following the Arrest of Seizure Activity

Siesjö

Hanwehr

Nergelius

et al. 1985

J Cereb Blood Flow Metab

157

View full text Add to dashboard Cite

Summary: The objective of the study was to estimate changes in extracellular pH (pHe) and intracellular pH (pH) during seizures and in the recovery period following the arrest of seizure activity. Seizures of 5-and 20-min duration were induced in rats by fluorothy! added to the insufflated gas mixture, and recovery for 5, 15, and 45 min was instituted by withdrawal of the fluorothyl supply following 20 min of continuous seizures. Changes in pHe were measured by double-barreled, liquid ion-exchange pH microelectrodes, and in pHj by the CO2 method, fol lowing estimation of tissue Pco2 and extracellular fluid (ECF) volume. The animals were either normoxic or ren dered moderately hypoxic (arterial P02 40-50 mm Hg). Upon induction of seizures in normoxic animals, pHe de creased by a mean of 0.36 unit, the values being identical at 5 and 20 min. In moderate hypoxia, seizures sustained for 20 min were accompanied by a further fall in pHe (mean decrease 0.51 unit). The changes in pHe seemed mainly to reflect the nonionic diffusion of lactic acid from cells to the ECF (tissue lactate levels -10 and 15 fLmol g-l during seizures in norm oxic and hypoxic animals, respectively). However, the gradual fall in pHe attribut able to lactic acid production was preceded by rapid acid ification, sometimes exceeding the steady-state values subsequently attained. This acidification was interpreted Seizures induced in normo-or hyperglycemic an imals invariably lead to tissue lactic acidosis. During sustained seizures, the tissue lactate content increases to, and remains at, values of 8-10 !-lmol g-l (Duffy et aI., 1975; Chapman et aI., 1977; Fol bergrova et aI., 1981 Abbreviations used: ECF, extracellular fluid; pHe' extracel lular pH; pHj, intracellular pH; P,c02, tissue CO2 tension; Tc02, total tissue CO2 content. 47to reflect spreading depression and fast transcellular Na + / H+ exchange. Following cessation of seizure discharge, pHe normalized at a surprisingly slow rate, with some acidosis persisting even after 45 min. The difference be tween cerebrovenous and arterial Pco2 was reduced during seizures and increased in the recovery period, probably reflecting alterations in the blood flow/meta bolic rate coupling. Impedance changes were slight, in dicating only minor changes in ECF volume. Changes in pHj after 5 min of seizures ranged from 0.20 (norm oxic animals) to 0.32 (hypoxic animals) unit, the pHj values after 20 min being 0.07 -0.08 unit higher. The results sug gest the regulation of pHj during ongoing seizures. Upon arrest of seizure activity, pHj rapidly increased to normal and subsequently to supranormal values. Postepileptic in tracellular alkalosis occurred at a time when pHe was still reduced and in spite of the fact that tissue lactate values had not normalized. It is concluded that the rapid nor malization of pHj and overt alkalosis were caused by the simultaneously occurring oxidation of lactate, with the removal of a stoichiometrical amount of H+, and the ex trusion of H+ from cells, possibly via a Na+/H+ ex chang...

show abstract

Section: Experimental Seriesmentioning

confidence: 99%

Extra- and Intracellular pH in the Brain during Seizures and in the Recovery Period following the Arrest of Seizure Activity

Siesjö

Hanwehr

Nergelius

et al. 1985

J Cereb Blood Flow Metab

157

View full text Add to dashboard Cite

show abstract

“…Indeed, these sensors are routinely used in all types of clinical analyzers to determine electrolyte concentrations in blood and other physiological samples [13,14]. Potentiometric microelectrodes are used in physiology for single cell electrolyte detection [15]. Environmental applications are also routinely known.…”

Section: The Trouble Of Direct Potentiometrymentioning

confidence: 99%

Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing

Bakker

Bhakthavatsalam

Gemene

2008

Talanta

View full text Add to dashboard Cite

For about one hundred years, potentiometry with ion-selective electrodes has been one of the dominating electroanalytical techniques. While great advances in terms of selective chemistries and materials have been achieved in recent years, the basic manner in which ion-selective membranes are used has not fundamentally changed. The potential readings are directly co-dependent on the potential at the reference electrode, which requires maintenance and for which very few accepted alternatives have been proposed. Fouling or clogging of the exposed electrode surfaces will lead to changes in the observed potential. At the same time, the Nernst equation predicts quite small potential changes, on the order of millivolts for concentration changes on the order of a factor two, making frequent recalibration, accurate temperature control and electrode maintenance key requirements of routine analytical measurements. While the relatively advanced selective materials developed for ion-selective sensors would be highly attractive for low power remote sensing application, one should consider solutions beyond classical potentiometry to make this technology practically feasible. This paper evaluates some recent examples that may be attractive solutions to the stated problems that face potentiometric measurements. These include high amplitude sensing approaches, with sensitivities that are order of magnitude larger than predicted on the Nernst equation; backside calibration potentiometry, where knowledge of the magnitude of the potential is irrelevant and the system is evaluated from the backside of the membrane; controlled current coulometry with ionselective membranes, an attractive technique for calibration free reagent delivery without the need for standards or volumetry; localized electrochemical titrations at ion-selective membranes, making it possible to design sensors that directly monitor parameters such as total acidity for which volumetric techniques were traditionally used; and controlled potential coulometry, where all ions of interest are selectively transferred into the ion-selective organic phase, forming a calibration free technique that would be exquisitely suitable for remote sensing applications. KeywordsIon-selective electrodes; chemical sensors; reference electrode; calibration free; coulometry; remote sensing Direct Potentiometry: The State of the Art and Promise for Remote SensingIon-selective electrodes are among the oldest known types of chemical sensors [1]. In most cases, an ion-selective membrane separates the sample from an inner solution, and the electromotive force between reference electrodes in the aqueous sample and the inner solution Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the p...

show abstract

“…Then, tube B was backfilled with the liquid ion exchanger until the exchanger column was 70-100 pm in length from the tip. The remaining portion of tube B was filled with a phosphate-buffered solution (40 mM KH2PO4, 23 mM NaOH and 15 mM NaCI) (36) for a pH sensor. Reference tube A was backfilled with 0.5 M KCI.…”

Section: Double Barreled Ion-selective Microelectrodesmentioning

confidence: 99%

Effects of Stilbene Derivatives SITS and DIDS on Development of Intracellular Acidosis during Ischemia in Isolated Guinea Pig Ventricular Papillary Muscle In Vitro

Lai

Liu

Nishi

1996

Japanese Journal of Pharmacology

View full text Add to dashboard Cite

ABSTRACT-Using ion-selective microelectrode techniques, we investigated the effects of 4-acetamido-4'-isothiocyanatostilbene-2,2 disulfonic acid (SITS) and 4,4' -diisothiocyanostilbene-2,2 disulfonic acid (DIDS), which are known as Cl--HCO3-exchange blockers, on action potentials and intracellular pH (pH;) in guinea pig ventricular papillary muscles subjected to simulated ischemia. Simulated ischemia was produced by stopping the flow of superfusing solution and then covering the preparations with mineral oil. Simulated ischemia induced a progressive decrease in the maximum upstroke rate and resting membrane potentials, shortened action potential duration, and resulted in cessation of action potentials within 10-12 min after the onset of simulated ischemia. The pH;-measurements revealed progressive intracellular acidosis during the period of simulated ischemia. SITS (0.5 mM) or DIDS (0.1 mM) delayed the onset of ischemiainduced deterioration of action potentials and prolonged the time to cessation of action potentials. SITS or DIDS (0.1-0.5 mM) induced an increase in pH, in HCO3--buffered solution and suppressed the development of intracellular acidosis during ischemia. Under the external Cl--free condition, the time to cessation of action potentials caused by ischemia was significantly delayed, and the development of intracellular acidosis during ischemia was attenuated. The present results indicate that activation of the Cl--HC03-exchange system would be involved, in part, in the development of intracellular acidosis during cardiac ischemia.

show abstract

Neutral carrier based hydrogen ion selective microelectrode for extra- and intracellular studies

Cited by 384 publications

References 23 publications

Extra- and Intracellular pH in the Brain during Seizures and in the Recovery Period following the Arrest of Seizure Activity

Extra- and Intracellular pH in the Brain during Seizures and in the Recovery Period following the Arrest of Seizure Activity

Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing

Effects of Stilbene Derivatives SITS and DIDS on Development of Intracellular Acidosis during Ischemia in Isolated Guinea Pig Ventricular Papillary Muscle In Vitro

Contact Info

Product

Resources

About