title: Multiple quantum filtered (23)Na NMR in the Langendorff perfused mouse heart: Ratio of triple/double quantum filtered signals correlates with [Na]i.
abstract: We investigate the potential of multiple quantum filtered (MQF) (23)Na NMR to probe intracellular [Na]i in the Langendorff perfused mouse heart. In the presence of Tm(DOTP) shift reagent the triple quantum filtered (TQF) signal originated largely from the intracellular sodium pool with a 32±6% contribution of the total TQF signal arising from extracellular sodium, whilst the rank 2 double-quantum filtered signal (DQF), acquired with a 54.7° flip-angle pulse, originated exclusively from the extracellular sodium pool. Given the different cellular origins of the (23)Na MQF signals we propose that the TQF/DQF ratio can be used as a semi-quantitative measure of [Na]i in the mouse heart. We demonstrate a good correlation of this ratio with [Na]i measured with shift reagent at baseline and under conditions of elevated [Na]i. We compare the measurements of [Na]i using both shift reagent and TQF/DQF ratio in a cohort of wild type mouse hearts and in a transgenic PLM(3SA) mouse expressing a non-phosphorylatable form of phospholemman, showing a modest but measurable elevation of baseline [Na]i. MQF filtered (23)Na NMR is a potentially useful tool for studying normal and pathophysiological changes in [Na]i, particularly in transgenic mouse models with altered Na regulation.
authors.affiliation: Department of Imaging Chemistry and Biology, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London SE1 7EH, United Kingdom; The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom. Electronic address: thomas.eykyn@kcl.ac.uk.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Eykyn
authors.affiliation: The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
authors.forename: Dunja
authors.initials: D
authors.lastname: Aksentijević
authors.affiliation: The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Aughton
authors.affiliation: Department of Imaging Chemistry and Biology, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London SE1 7EH, United Kingdom; The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Southworth
authors.affiliation: Division of Cardiovascular and Diabetes Medicine, University of Dundee, Dundee, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: Fuller
authors.affiliation: The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Shattock
mesh_terms: D000818:Animals; D006321:Heart / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000067268:Isolated Heart Preparation; D008279:Magnetic Resonance Imaging; D051379:Mice; D009206:Myocardium / Q000378:metabolism*; D011859:Radiography; D012964:Sodium / Q000378:metabolism; D012979:Sodium Radioisotopes / Q000008:administration & dosage / Q000378:metabolism
chemical_list: D012979:Sodium Radioisotopes; D012964:Sodium
keywords: DQF; Langendorff perfused mouse heart; Multiple quantum filtered (23)Na; Shift reagent; TQF