Abstract
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 language | English (US) |
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Pages (from-to) | 111-116 |
Number of pages | 6 |
Journal | BBA - Molecular Cell Research |
Volume | 1177 |
Issue number | 2 |
DOIs | |
State | Published - Jun 6 1993 |
Externally published | Yes |
Keywords
- (Rat)
- (Salivary gland)
- NMR, Na-
- Sodium ion, intracellular
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology