| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1989: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1988: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
The introduction of new paramagnetic shift reagent in the nuclear magnetic resonance (NMR) method has made it possible to distinguish intra- and extracellular ions in tissues or organs in vitro. However, such measurements in organs in vivo have not yet been reported. In the present investigation, we attempted to measure the intra- and extracellular ^<23>Na and ^1H in vivo in the gerbil brain and skeletal muscle by NMR spectroscopy employing the shift reagent, dysprosium triethylenetetraminehexaacetate, Dy(TTHA)^<3->. Without Dy(TTHA)^<3->, the ^<23>Na and ^1H signals were seen only as single peaks. Gradual intravenous infusion of 300 mM DY(TTHA)^<3-> caused little blood pressure reduction and no change in electroencephalogram which was recorded simultaneously with the NMR spectroscopy. After 2 hours of DY(TTHA)^<3-> infusion, the ^<23>Na and ^1H signals were into two peaks, respectively. The unshifted peaks reflected the intracellular ^<23>Na and ^1H signals, whereas the shifted peaks reflected the extracellular signals. In the brain spectra, an additional small peak, which represented intravascular signals, was detected, and its intensity increased after injection of papaverine hydrochloride. The present method is advantageous over the microelectrode technique because of its nondestructiveness and its capability for obtaining intra- and extracellular volume information from measurements of the ^1H spectra, the peaks of which reflect the intra- and extracellular water amounts. The technique is clearly of use for physiological and pathophysiological studies of organs.
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