| Project/Area Number |
07680719
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics
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| Research Institution | Osaka University |
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Principal Investigator |
NAKAOKA Yasuo Osaka University, Faculty of Engineering Science, Department of Biophysical Engineering, Associate Professor, 基礎工学部, 助教授 (90029562)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMIZU Kikuo Osaka University, Radioisotope Research Center, Research Associate, RI総合センター, 助手 (20162696)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1995: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Sensory receptor / Temperature / Ca^<2+> / Prostaglandin / Paramecium / Mast cell / ATP receptor / イオン・チャネル |
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| Research Abstract |
Paramecium cells respond to a temperature drop from the culture temperature and transiently depolarize the membrane, which triggers the directional changes in the swimming. We found that when the cells respond to the temperature drop, the intracellular Ca^<2+> transiently increased. The Ca^<2+> increase was restricted to the anterior part of the cell, corresponding to the sensitive part to the temperature drop. It was shown that the Ca^<2+> increase was caused by an influx of external Ca^<2+>.
Some chemicals which seem to inhibit prostaglandin (PG) synthesis of Paramecium also inhibited the response to the temperature drop. On the other hand, when some PG were applied to the cell, the response to the temperature drop was recovered. The Paramecium cell has a sensitiviy to PG and showed a transient response when applied to the anterior part of the cell. These results suggest the possibility that the thermo-reception has some relationship to the prostaglandin receptor. Details of the relationship must be studied further.
Rat mast cell line (RBL-2H3) was tested for the response to the temperature drop by the measurements of intracellular Ca^<2+>. When ATP was added in the external medium, the cells became to respond to the temperarure drop, and showed a transient increase in the intracellular Ca^<2+>. The Ca^<2+> increase was caused by the liberation from internal Ca^<2+> stores. Pharmacological analyzes showed that the ATP receptor has the sensitivity to the temperature drop. Activation mechanism of the ATP receptor remains to be elucidated further in the molecular level.
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