| Co-Investigator(Kenkyū-buntansha) |
AZUMA Yasuyoshi Research Institute of Environmental Sciences, Environmantal Toxicology Unit, Res, 環境毒生部, 研究員
IRIE Masakazu Osaka Agricultural Research Center, Livestock Divislon, Researcher, 畜産部, 主任研究員
ISHII Takashi Kyoto University, Department of Animal Sciences, Assistant, 農学部, 助手 (70111945)
MANABE Noboru Kyoto University, Department of Animal Sciences, Associate Professor, 農学部, 助教授 (80243070)
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| Research Abstract |
In vivo and in vitro phosphorus-31 and proton nuclear magnetic resonance (NMR) spectra of the ovary, liver, skeletal muscle and embryo of experimental and farm animals were acquired using a house-made surface coil, conventional round coil, and/or imaging coils. Beta-ATP/inorganic phosphate ratio which represents the high energy state and intracellular pH etc.were observed in vivo. Many environmental toxicants were identified and quantified without any extraction processes from these organs and embryos using a NMR spectroscopy. Proton NMR experiments were done by a modification of conventional techniques, and 31P NMR experiments were performed as follows : During the NMR examination, the sample was maintained in a probe chamber at controlled air temperature of 25. C.In.vivo 31P NMR spectra of the steady-state organs within intact animals were obtained using a JNM-alpha-400 FT-NMR spectromenter (JEOL,Tokyo, Japan) equipped with 89-mm bore super-conducting magnet (9.20 Tesla ; Oxford Inst
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ruments, Bedford, MA,USA). The animal was mounted on a surface coil probe (two-turns, 2.0cm diameter) with was tuned to 31P at 161.7MHz and used in conjunction with a ferrite screen composed of strips of computer tape (Scotch 700 ; Three M Co., St.Louis, MO) to eliminate 31P NMR signals arising from superficial muscles (7). Field homogeneity was controlled by adjusting shim parameters using a water 1H signal derived from the organ sample. Acquisition conditions were set as follows to obtain fully relaxd signals : the pulse width was 20 micro-seconds, the pulse repetition time was 3.0s, and 200 scans were accumulated. Thus, it took 5-25 min for each measurement. After exponential multiplication, the accumulated free induction decays were subjected to Fourier transformation. Individual spectral peak areas were calculated by computer integration with JEOL software (JEOL), and the creatine phosphate (CP) peak was used as a positional reference (0 ppm). The relative amount of each compound was converted to absolute concentration by comparison with the data of an external reference (20mM methylene diphosphonate in water) in a spherical bulb. The present study showed that NMR spectroscopy is a novel assessment tools for assessment of reproductive and genetic toxicity in experimental and domestic animals. Less
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