MEASUREMENT OF INTRACELLULAR NA IN THE RAT SALIVARY-GLAND - A NA-23 NMR-STUDY USING DOUBLE QUANTUM FILTERING

23Na in the prefused rat mandibular salivary gland was measured by spin-echo double quantum filter 23Na-NMR spectroscopy at 8.45 T. Resonances due to the intracellular 23Na and the interstitial 23Na were observed in the perfused gland at 25°C. The resonance due to intracellular 23Na consisted of two Lorentzian signals stemming from the | 1 2〉〈 -1 2| coherence (sharp resonance) and the | -1 2〉〈 -3 2| and | 3 2〉〈 1 2| coherences (broad resonance). The transverse relaxation rate constant corresponding to the | 1 2〉〈 -1 2| coherence was 95 ± 4 s-1 and that corresponding to the | -1 2〉〈 -3 2| and | 3 2〉〈 1 2| coherences was 1360 ± 75 s-1 (ean ± S.E., n = 5). The resonance due to the interstitial 32Na had longer relaxation rate constants, and disappeared upon administration of dysprosium triethylenetetramine-N,N′,N″,N‴,N‴-hexaacetic acid. © 1990.