An analysis of intracellular 23Na relaxation using the double-quantum filtered NMR signal from the perfused rat salivary gland

Yoshiteru Seo, William D. Rooney, Masataka Murakami

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The intracellular sodium of the perfused rat mandibular salivary gland was measured by double-quantum filtered 23Na-NMR spectroscopy at 2.34, 4.7 and 8.45 T. Biexponential relaxation of the intracellular 23Na signal was observed, and its intensity was increased by administration of acetylcholine with ouabain at 25°C. The transverse and longitudinal relaxation rate constants were determined by the 'transverse experiment' (D-90°-τ/2-180°-τ/2-90°-δ-90°-acquire) and the 'longitudinal experiment' (D-180°-τ-54.7°-δ-90°-acquire), respectively. From observed dependencies on B0 and temperature (5-37°C), a possibility of exchange between two populations of intracellular Na+ was suggested. A small fraction of Na+ is in the slow-motion condition (with a quadrupole coupling constant of approx. 1.75 MHz and a correlation time of 6·10-8 s). The major portion of intracellular Na+ is in the extreme narrowing condition with a transverse relaxation rate constant of approx. 100 s-1, which corresponds to a viscosity of approx. 5 cP.

Original languageEnglish (US)
Pages (from-to)111-116
Number of pages6
JournalBBA - Molecular Cell Research
Issue number2
StatePublished - Jun 6 1993



  • (Rat)
  • (Salivary gland)
  • NMR, Na-
  • Sodium ion, intracellular

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

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