1989 Fiscal Year Final Research Report Summary
ESTIMATION OF CEREBRAL INTRA- AND EXTRACELLULAR Na^+ CONCENTRATION BY IN VIVO MAGNETIC RESONANCE SPECTROSCOPY WITH SHIFT REAGENT
| Project/Area Number |
63570377
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Neurology
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| Research Institution | NATIONAL CARDIOVASCULAR CENTER |
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Principal Investigator |
NARITOMI Hiroaki National Cardiovascular Center Cerebral Circulation Laboratory Director, 循環動態機能部, 室長 (60132932)
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| Co-Investigator(Kenkyū-buntansha) |
SASAKI Masahiro National Cardiovascular Center Radio-Isotope Experimental Institute Faculty, RI施設, 研究員 (50150800)
KANASHIRO Masaru National Cardiovascular Center Department of Biochemistry Faculty, 共通実験室, 研究員 (10132929)
NARITOMI Hiroaki National Cardiovascular Center Cerebral Circulation Laboratory Director (60132932)
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| Project Period (FY) |
1988 – 1989
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| Keywords | 23Na-NMR Spectroscopy / Intracellular Na+ concentration / Shift Reagent |
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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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Research Products
(2 results)
