報告書番号

U00076

タイトル（和文）

ラット神経細胞（小脳顆粒細胞）のチロシンのリン酸化に対する50Hz磁界の影響

タイトル（英文）

Effect of 50Hz magnetic fields on tyrosine phosphorylation in rat cerebellar granule neurons

概要 （図表や脚注は「報告書全文」に掲載しております）

生後7日目のSDラットから小脳を解剖して取り出し、小脳顆粒細胞を37℃、5% 二酸化炭素濃度、湿度95%以上の培養条件下で4日間培養後、チロシンキナーゼのチロシンリン酸化の外部刺激に対する応答を細胞の脱分極で磁界曝露実験の陽性対照実験として観察した。脱分極後、複数のチロシンキナーゼのチロシンリン酸化に変化が観察され、電気的な刺激に正常に応答することが分かった。陽性対照と同様に培養後4日目の小脳顆粒細胞にワイドレンジ磁界曝露設備を用いて、50Hz、14.1または1.41mTrmsの回転円磁界を60分間曝露し細胞を回収後、ウエスタン-イムノブロット法を用いてチロシンキナ－ゼのチロシンリン酸化について分析した。結果、14.1mTrmsの回転円磁界で約60kDaのリン酸化に弱いながらも上昇が観察されたが、1.41mTrmsの回転円磁界では観察されなかった。

概要 （英文）

Tyrosine phosphorylation is a form of intracellular signal transduction involving tyrosine kinases and it is an important system for a cell regulation. Abnormality in the regulation of tyrosine kinases can induced many drastic changes for cells such as proliferation, transformation and apoptosis. I reported enhancement of tyrosine phosphorylation in HL60 cells after exposure to 14.1mTrms of sinusoidal 50 Hz magnetic fields for 60min. The objective of this study is to detect similar responses in cerebellar granule neurons. Firstly, I investigated the effect of depolarization on tyrosine phosphorylation in cerebellar granule neurons for positive control. Cerebellar granule neurons isolated from postnatal day 7 SD rats and grown in TC flasks under 37℃, 5% CO2，>95% humidity for 4days were stimulated by depolarization using 25mM potassium. Tyrosine phosphorylation was analyzed by western immuno-blotting using specific anti body against phosphorylate tyrosine kinase. Some tyrosine phosphorylations were changed by depolarization in time dependent manner. Secondly, I investigated the effect of magnetic fields on tyrosine phosphorylation in cerebellar granule neurons. A Merritt-coil system (a wide-range magnetic fields exposure system) was used to expose magnetic fields (MFs) in this study producing maximum 14.1mTrms (circularly polarized) MFs at sinusoidal 50 Hz. Dissection, cell culture and western immuno-blotting were used same protocols of depolarization. Enhancement of approximately 60kDa tyrosine phosphorylation was detected after exposure to 14.1mTrms MFs for 60min, but not to 1.41mTrms MFs for 60min and analyzed by the same protocols as 14.1mTrms exposure. These results suggested that effect of MFs on tyrosine phosphorylation was detected only 14.1mTrms, and 1.41mTrms exposure did not effect the tyrosine phosphorylation.

報告者

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