Factors affecting <sup>39</sup>K NMR detectability in rat tissue

Rashid, Shazia; Adam, W. R.; Craik, David J.; Shehan, B. Philip; Wellard, R. Mark

doi:10.1002/mrm.1910170124

Cited by 15 publications

(9 citation statements)

References 16 publications

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“…While the intracellular sodium has been found to be totally visible in perfused hearts (24, 28,38), and the extracellular sodium has been found to be totally visible in the extracellular space in cartilage ( 3 9 ) , the possibility that the NMR visibility changes with pathology in either the intracellular or extracellular spaces must always be kept in mind. The specific experimental conditions chosen are responsible for the NMR visibility (28,38,40).…”

Section: Discussionmentioning

confidence: 99%

Characteristics of extracellular sodium relaxation in perfused hearts with pathologic interventions

Foy

Burstein

1992

Magnetic Resonance in Med

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Sodium spectroscopy and imaging sequences designed to emphasize fast T2 decay or the multiple quantum signal have previously demonstrated a high contrast between normal and pathologic tissue which may be due to changes in intracellular versus extracellular sodium distribution. Since alterations in the amount of signal with fast T2 decay have previously been shown to occur with changes in intracellular sodium content, this study investigated the fast T2 relaxation characteristics of extracellular sodium during pathologic interventions on nonsubmerged perfused rat hearts. T2 data on total sodium content were obtained while global ischemia (stopping all perfusate flow) and extracellular edema (due to long perfusion times) were induced in the heart. The data were fit to a biexponential, with Mf(T2f) the magnitude (time constant) of the fast component of decay. Mf increased significantly in both pathologies (to 319 +/- 26%, n = 3, of baseline for ischemia and to 527 +/- 284%, n = 3, of baseline for edema); the increase with edema was demonstrated to be due to extracellular sodium by intermittently perfusing the heart for a short period with shift reagent. When shift reagent was not used until the conclusion of the edema experiment, Mf increased to 169 +/- 35% of baseline, also due mainly to extracellular sodium. T2f did not exhibit any trends with these experiments, with values ranging from 1.7 to 5.5 ms. We believe that these results indicate that compartmental sodium content will most likely not be quantifiable in pathologic states in the heart with relaxation-based techniques. However, correlations between the pathologic state of the tissue and the sodium NMR signal obtained with pulse sequences or images that emphasize a particular aspect of relaxation may prove to be useful.

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Section: Discussionmentioning

confidence: 99%

Characteristics of extracellular sodium relaxation in perfused hearts with pathologic interventions

Foy

Burstein

1992

Magnetic Resonance in Med

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“…Technical developments to increase the utility of 23 Na continue [147,148]. In vivo studies using 39 K have been more limited, as they are even more challenging than 23 Na studies [149,150]. 23 Na and 39 K studies in cells and perfused organs may take advantage of the use of shift reagents, anionic chelated complexes of paramagnetic lanthanides such as dysprosium bis(tripolyphosphate) (Dy(PPPi) 2 7-), which shift the frequencies of the extracellular ions sufficiently away from the intracellular resonances to resolve the difference [151][152][153].…”

Section: Myoinositol: An Indicator Of Inflammation and A Putative Markementioning

confidence: 99%

Quantitative Analysis in Magnetic Resonance Spectroscopy: From Metabolic Profiling to In Vivo Biomarkers

Serkova

Brown

2012

Bioanalysis

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Nuclear magnetic resonance spectroscopy (called NMR for ex vivo techniques and MRS for in vivo techniques) has become a useful analytical and diagnostic tool in biomedicine. In the past two decades, an MR-based spectroscopic approach for translational and clinical research has emerged that allows for biochemical characterization of the tissue of interest either ex vivo (NMR-based metabolomics) or in vivo (localized MRS-single voxel or multivoxel-spectroscopic imaging). The greatest advantages of MRS techniques are their ability to detect multiple tissue-specific metabolites in a single experiment, their quantitative nature and translational component (in vitro/ex vivo-discovered metabolic biomarkers can be translated into noninvasive spectroscopic imaging protocols). Disadvantages of MRS include low sensitivity and spectral resolution and, in case of NMR-metabolomics, metabolite degradation and incomplete recovery in processed samples. In vivo MRS has worse spectral resolution than ex vivo high-resolution NMR due to the inherently wider lines of metabolites in vivo and the difficulty of using traditional line-narrowing methods (e.g., sample spinning). It also suffers from poor time-resolution, therefore offering fewer metabolic biomarkers to be followed in vivo. In the present review article, we provide considerations for establishing reliable protocols (both in vivo and ex vivo) for metabolite detection, recovery and quantification from in vivo and ex vivo MR spectra.

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“…Similarly, a TmDOTP shift reagent was used to assist 39 K NMR measurement of intracellular potassium during ischemia in the perfused guinea pig heart [234]. A number of studies have demonstrated the usefulness of 39 K NMR for in vivo measurement of potassium levels and its transport in a range of different rat tissues including blood, brain, muscle, kidney, liver, testes and mandibular salivary gland [235][236][237][238]. A number of feasibility studies have also been performed for 39 K-MRI analysis of human muscle ( Figure 17) and brain [239][240][241].…”

Section: F Ementioning

confidence: 99%

NMR-Active Nuclei for Biological and Biomedical Applications

Patching¹

2016

J Diagn Imaging Ther

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Nuclear magnetic resonance (NMR) spectroscopy is a principal well-established technique for analysis of chemical, biological, food and environmental samples. This article provides an overview of the properties and applications of NMR-active nuclei (39 nuclei of 33 different elements) used in NMR measurements (solution-and solid-state NMR, magnetic resonance spectroscopy, magnetic resonance imaging) with biological and biomedical systems and samples. The samples include biofluids, cells, tissues, organs or whole body from different organisms (humans, animals, bacteria, fungi, plants) for detecting and quantifying metabolites or environmental samples (water, soils, sediments). Isolated biomolecules (peptides, proteins, nucleic acids) can be analysed for elucidation of atomic-resolution structure, conformation and dynamics and for characterisation of ligand and drug binding, and of protein-ligand, protein-protein and protein-nucleic acid interactions. NMR can be used for drug screening and pharmacokinetics and to provide information in the design and discovery of new drugs. NMR can also measure translocation of ions and small molecules across lipid bilayers and membranes, characterise structure, phase behaviour and dynamics of membranes and elucidate atomic-resolution structure, orientation and dynamics of membrane-embedded peptides and proteins.Keywords: biological and biomedical applications; drug screening; dynamics; magnetic resonance imaging; membrane proteins; metabolomics; MRI; NMR-active nuclei; nuclear magnetic resonance; protein structure INTRODUCTION1 UCLEAR magnetic resonance (NMR) spectroscopy is one of the principal techniques used for analysis of biological and biomedical systems and samples. This can include the identification, quantification and monitoring of ions, small molecules and biomolecules in studies of metabolism and biological function in human and animal cells and tissues, bacterial cells and spores, fungi and plants. Similar types of measurements can be performed on environmental samples such as water, soils and sediment. NMR is able to elucidate atomic-resolution structure, conformation, molecular mechanism, dynamics and exchange processes (on timescales of picoseconds to seconds) in biomolecules, especially peptides, proteins and nucleic acids. NMR can be used for the observation, quantification and characterisation of ligand and drug binding to biomolecules, and for characterisation of ligandprotein, protein-protein and protein-nucleic acid interactions. NMR can be used for drug screening and it can acquire structural, binding and kinetic information for the design and discovery of new drugs. It can then monitor the absorption, distribution, metabolism and excretion (ADME) of administered drugs in pharmacokinetics studies. OPEN ACCESS PEER-REVIEWED*NMR can be used for the observation, quantification and kinetic characterisation of ion and smallmolecule translocation across lipid bilayers and biological membranes, including those of cells, tissues and vesicles. Solid-state NM...

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Factors affecting ³⁹K NMR detectability in rat tissue

Cited by 15 publications

References 16 publications

Characteristics of extracellular sodium relaxation in perfused hearts with pathologic interventions

Characteristics of extracellular sodium relaxation in perfused hearts with pathologic interventions

Quantitative Analysis in Magnetic Resonance Spectroscopy: From Metabolic Profiling to In Vivo Biomarkers

NMR-Active Nuclei for Biological and Biomedical Applications

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Factors affecting 39K NMR detectability in rat tissue

Cited by 15 publications

References 16 publications

Characteristics of extracellular sodium relaxation in perfused hearts with pathologic interventions

Characteristics of extracellular sodium relaxation in perfused hearts with pathologic interventions

Quantitative Analysis in Magnetic Resonance Spectroscopy: From Metabolic Profiling to In Vivo Biomarkers

NMR-Active Nuclei for Biological and Biomedical Applications

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Factors affecting ³⁹K NMR detectability in rat tissue