Determination of chloride potential in perfused rat hearts by nuclear magnetic resonance spectroscopy

R. Ramasamy, P. Zhao, W. L. Gitomer, A. D. Sherry, C. R. Malloy

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Isolated beating rat hearts were perfused with trifluoroacetamide (TFM) and trifluoroacetate (TFA) and monitored by 19F-nuclear magnetic resonance (NMR). The average membrane TFA potential in spontaneously beating rat hearts, calculated according to standard principles assuming that TFA is distributed in its anionic form, was found to be -36.2 ± 3.2 mV (n = 9) under normoxic conditions. In separate experiments, the chloride and potassium potentials were determined to be -38.5 ± 3.6 mV (n = 7) and -85.3 ± 3.3 mV (n = 7), respectively, from freeze-clamped heart tissue. In the presence of the anion-exchange inhibitor, 4-acetamido-4'- isothiocyanostilbene-2,2'-disulfonic acid (SITS), TFA uptake into heart was significantly reduced, suggesting that TFA uptake occurs partly via the Cl- -HCO3/- exchanger. Based on these results and the results of R. E. London and S. A. Gabel (Biochemistry 28:2378-2382, 1989), we conclude that the distribution of TFA in hearts reflects the chloride potential (E(Cl)) and not the membrane potential. A time-dependent change in the E(Cl) occurs during global ischemia, and changes in E(Cl) were also observed when the hearts were perfused with high concentrations of KCl. These results demonstrate that 19F-NMR may be utilized to monitor the E(Cl) of perfused hearts under a variety of conditions.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume263
Issue number6 32-6
StatePublished - 1992

Fingerprint

Trifluoroacetic Acid
Chlorides
Magnetic Resonance Spectroscopy
Membrane Potentials
4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid
Chloride-Bicarbonate Antiporters
Potassium Chloride
Biochemistry
Anions
Ischemia
Acids

Keywords

  • intracellular volume
  • myocardial ischemia
  • potassium chloride arrest
  • trifluoroacetate

ASJC Scopus subject areas

  • Physiology

Cite this

@article{9a85315699a3452c81296ae4b21cee9e,
title = "Determination of chloride potential in perfused rat hearts by nuclear magnetic resonance spectroscopy",
abstract = "Isolated beating rat hearts were perfused with trifluoroacetamide (TFM) and trifluoroacetate (TFA) and monitored by 19F-nuclear magnetic resonance (NMR). The average membrane TFA potential in spontaneously beating rat hearts, calculated according to standard principles assuming that TFA is distributed in its anionic form, was found to be -36.2 ± 3.2 mV (n = 9) under normoxic conditions. In separate experiments, the chloride and potassium potentials were determined to be -38.5 ± 3.6 mV (n = 7) and -85.3 ± 3.3 mV (n = 7), respectively, from freeze-clamped heart tissue. In the presence of the anion-exchange inhibitor, 4-acetamido-4'- isothiocyanostilbene-2,2'-disulfonic acid (SITS), TFA uptake into heart was significantly reduced, suggesting that TFA uptake occurs partly via the Cl- -HCO3/- exchanger. Based on these results and the results of R. E. London and S. A. Gabel (Biochemistry 28:2378-2382, 1989), we conclude that the distribution of TFA in hearts reflects the chloride potential (E(Cl)) and not the membrane potential. A time-dependent change in the E(Cl) occurs during global ischemia, and changes in E(Cl) were also observed when the hearts were perfused with high concentrations of KCl. These results demonstrate that 19F-NMR may be utilized to monitor the E(Cl) of perfused hearts under a variety of conditions.",
keywords = "intracellular volume, myocardial ischemia, potassium chloride arrest, trifluoroacetate",
author = "R. Ramasamy and P. Zhao and Gitomer, {W. L.} and Sherry, {A. D.} and Malloy, {C. R.}",
year = "1992",
language = "English (US)",
volume = "263",
journal = "American Journal of Physiology - Heart and Circulatory Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "6 32-6",

}

TY - JOUR

T1 - Determination of chloride potential in perfused rat hearts by nuclear magnetic resonance spectroscopy

AU - Ramasamy, R.

AU - Zhao, P.

AU - Gitomer, W. L.

AU - Sherry, A. D.

AU - Malloy, C. R.

PY - 1992

Y1 - 1992

N2 - Isolated beating rat hearts were perfused with trifluoroacetamide (TFM) and trifluoroacetate (TFA) and monitored by 19F-nuclear magnetic resonance (NMR). The average membrane TFA potential in spontaneously beating rat hearts, calculated according to standard principles assuming that TFA is distributed in its anionic form, was found to be -36.2 ± 3.2 mV (n = 9) under normoxic conditions. In separate experiments, the chloride and potassium potentials were determined to be -38.5 ± 3.6 mV (n = 7) and -85.3 ± 3.3 mV (n = 7), respectively, from freeze-clamped heart tissue. In the presence of the anion-exchange inhibitor, 4-acetamido-4'- isothiocyanostilbene-2,2'-disulfonic acid (SITS), TFA uptake into heart was significantly reduced, suggesting that TFA uptake occurs partly via the Cl- -HCO3/- exchanger. Based on these results and the results of R. E. London and S. A. Gabel (Biochemistry 28:2378-2382, 1989), we conclude that the distribution of TFA in hearts reflects the chloride potential (E(Cl)) and not the membrane potential. A time-dependent change in the E(Cl) occurs during global ischemia, and changes in E(Cl) were also observed when the hearts were perfused with high concentrations of KCl. These results demonstrate that 19F-NMR may be utilized to monitor the E(Cl) of perfused hearts under a variety of conditions.

AB - Isolated beating rat hearts were perfused with trifluoroacetamide (TFM) and trifluoroacetate (TFA) and monitored by 19F-nuclear magnetic resonance (NMR). The average membrane TFA potential in spontaneously beating rat hearts, calculated according to standard principles assuming that TFA is distributed in its anionic form, was found to be -36.2 ± 3.2 mV (n = 9) under normoxic conditions. In separate experiments, the chloride and potassium potentials were determined to be -38.5 ± 3.6 mV (n = 7) and -85.3 ± 3.3 mV (n = 7), respectively, from freeze-clamped heart tissue. In the presence of the anion-exchange inhibitor, 4-acetamido-4'- isothiocyanostilbene-2,2'-disulfonic acid (SITS), TFA uptake into heart was significantly reduced, suggesting that TFA uptake occurs partly via the Cl- -HCO3/- exchanger. Based on these results and the results of R. E. London and S. A. Gabel (Biochemistry 28:2378-2382, 1989), we conclude that the distribution of TFA in hearts reflects the chloride potential (E(Cl)) and not the membrane potential. A time-dependent change in the E(Cl) occurs during global ischemia, and changes in E(Cl) were also observed when the hearts were perfused with high concentrations of KCl. These results demonstrate that 19F-NMR may be utilized to monitor the E(Cl) of perfused hearts under a variety of conditions.

KW - intracellular volume

KW - myocardial ischemia

KW - potassium chloride arrest

KW - trifluoroacetate

UR - http://www.scopus.com/inward/record.url?scp=0027096876&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027096876&partnerID=8YFLogxK

M3 - Article

VL - 263

JO - American Journal of Physiology - Heart and Circulatory Physiology

JF - American Journal of Physiology - Heart and Circulatory Physiology

SN - 0363-6135

IS - 6 32-6

ER -