| Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1985: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1984: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1983: ¥3,700,000 (Direct Cost: ¥3,700,000)
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| Research Abstract |
1. In vivo NMR: After several trials of NMR spectroscopy in the intact animal, we developed a new mwthod of sectional magnetic resonance (SMR). SMR employs the NMR character of phase inversion of the near sample and preservation of orthophase of distant sample.
2. EKG-gated SMR: The content of high energy phosphates, i.e., creatine phosphate(CP) and ATP, changes in cardiac cycle. In the present stufy, we used max(dV/dt) of the R wave in EKG II lead as a trigger to start SMR. Both contents of CP and ATP was the least at early 1/3 of the systole and maxiaml at the late 2/3 of the siastole. This is the first report of in vivo NMR spectroscopy in cardiac cycle.
3. Myocardial infarction model in rat and the SMR: After the administration of moderate to large dose of beta agonist, isoproterenol, caused subendocardial necrosis that is similar to the human subendocardial infarction. At the moderate dose, the signal intensity of sugar phospahte increased, and at the large doses, the signal intensity of CP, at first, and then ATP decreased, reflecting the myocardial degradation.
4. Combined study of SMR and <^1H> -NMR imaging: <^1H> -NMR imaginf is another excellent aspect of NMR. We used spin werp method for imaging and obtained a space resolution as small as 0.1 mm in a phantom. In the living rat the resolution decreased because of the cardiac motion and respiratory movement. At first, we visualized the rat left ventricle by the <^1H> -NMR imaging and adjusting the detecting area of <^(31)P> -SMR to the heart, we performed the SMR. The obtained results were similar to the resul shown in 2. These data suggest that the combination is promising for the exact quantification of cardiac metabolism.
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