1989 Fiscal Year Final Research Report Summary
Assessment of the Response of murine NR-S1 tumor following irradiation monitored by P-31 NMR Spectroscopy
| Project/Area Number |
63570486
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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 |
Radiation science
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| Research Institution | Faculty of Medicine, University of Tokyo |
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Principal Investigator |
ITOH Masamitsu University of Tokyo, Faculty of Medicine, Research assistant, 医学部(医), 助手 (80176362)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Shozo University of Tokyo, Research Institute of Medical Science, Research assistant, 医学部(医), 助手 (30012743)
YOSHIKAWA Kohki University of Tokyo, Faculty of Medicine, Lecturer, 医学部(医), 講師 (40114714)
SAITO Hazime National Cancer Center Institute, Division of Biophysics, Head, 室長 (30100150)
SUZUKI Norio University of Tokyo, Faculty of Medicine, Professor, 医学部(医), 室長 (10010050)
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| Project Period (FY) |
1988 – 1989
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| Keywords | P-31 MRS / Tumor Metabolism / Energy metabolism / Radiation therapy / Fractionated irradiation / Predictive assay / Neutron / X-irradiation |
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| Research Abstract |
The purpose of the present project is to assess the response of X-or Neutron irradiation to Murine NR-S1 tumor monitored by P-31 NMR Spectroscopy and to elucidate the radiosensitivity of this tumor from the point of energy metabolism, intracellular pH. Toward this goal, 3 subjects were set and have been carried out in parallel.
I. Normal growth of NR-S1 tumor During tumor growth, areas of metabolic deprivation develop which may be characterized by hypoxia and resultant reduction in high energy phosphates, including ATP, phosphocreatine (PCr) and pH.
II. Response of NR-S1 tumor following a single dose of X or Neutron irradiation After single dose of X-irradiation (25Gy, 5OGy), initial increase of Pi/PCr within 3-4 hours was occurred. The significant reduction of Pi/PCr was noted 2- 3 days after following irradiation. This phenomena may be a change in tumor cell metabolism with reoxygenation. In contrast, the same changes were noted after Neutron-irradiation in the doses (10GY, 2OGy) less than the dose of X- irradiation.
III. Response of NR-S1 tumor following fractionated X-irradiation In the even fractionated X-irradiation, the changes of energy metabolism were not significant more than the changes of the single dose irradiation. With 2 fractions of 25 Gy at interval of 4 hours or 24 hours, the recover rates of energy status 2-3 days after irradiation were mostly the same within these groups. In contrast, in the group of the split interval of 24 hours, the recovery was noted mostly significant.
In conclusion, P-31 MRS has been considerable for non-invasive investigation of tumor energy metabolism and which influence the outcome of most therapeutic modalities, including radiotherapy.
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