研究のタイプ: 医学/生物学の研究 (experimental study)

[超低周波電磁界ばく露は、マウス海馬のグルタミン酸レベルの変化、MAPK経路の活性化、CREBリン酸化減少を伴う認知障害を引き起こす:ハスの種子の鞘から抽出されたプロシアニジンによる反転] med./bio.

Extremely low frequency electromagnetic field exposure causes cognitive impairment associated with alteration of the glutamate level, MAPK pathway activation and decreased CREB phosphorylation in mice hippocampus: reversal by procyanidins extracted from the lotus seedpod

掲載誌: Food Funct 2014; 5 (9): 2289-2297

この研究は、超低周波電磁界ばく露(ELF-EMF:50Hz、8mT、28日間)がマウス海馬でのグルタミン放出変化を誘導
するか否かを調べた。また、ハスの種子の鞘から抽出されたプロシアニジン(LSPC)投与がこの変化を正常化すると仮定して、考え得るメカニズムを探求した。その結果、ELF-EMFばく露は、海馬グルタミンおよびGABAの含有量増加、NMDA受容体の過剰な活性化、NMDA受容体2B(NR2B)の数の増加、細胞内カルシウムイオン濃度上昇を誘導した;これらの変化に関連した遺伝子発現が見られた;LSPCの経口投与は、影響を抑制する遺伝子発現を改善した、などを報告している。

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研究目的(著者による)

To investigate whether an extremely low frequency magnetic field influences the glutamate release in the hippocampus of mice and to examine possible molecular mechanism, as well as the effects of lotus seedpod procyanidins (LSPC) administration.

詳細情報

In a previous study, the authors found that exposure to extremely low frequency magnetic fields could induce oxidative stress and influence the cognitive performance in mice and that an administration of LSPCs could prevent those impairments (Duan et al., 2013). However, the molecular mechanisms remained unknown.
Five groups of mice were examined (n=10 per group): 1.) sham exposure, 2.) exposure, 3.) exposure + 30 mg/kg LSPC, 4.) exposure + 60 mg/kg LSPC and 5.) exposure + 90 mg/kg LSPC. The LSPCs were administered daily for 43 days (15 days before the exposure and during the 28 days of exposure).

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 50 Hz
ばく露時間: 4 h/day for 28 days

ばく露1

主たる特性
周波数 50 Hz
タイプ
  • magnetic field
ばく露時間 4 h/day for 28 days
ばく露装置
ばく露の発生源/構造
チャンバの詳細 mice were exposed in well ventilated perspex boxes (14 cm x 10 cm x 12 cm) and these boxes were placed in the middle of the coils, temperature in the boxes was 23 ± 0.5°C
ばく露装置の詳細 pair of helmholtz coils (1 mm wire diameter, 32 cm internal diameter, 36 cm external diameter) with 500 turns was used; exposure device was placed in a temperature controlled room (23 ± 2°C)
Sham exposure A sham exposure was conducted.
パラメータ
測定量 種別 Method Mass 備考
磁束密度 8 mT - 測定値 - -

ばく露を受けた生物:

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
研究対象とした臓器系:
調査の時期:
  • ばく露後

研究の主なアウトカム(著者による)

In the hippocampus of exposed mice, the concentrations of glutamate, gamma aminobutyric acid, calcium ions and the protein expression level of the NMDA receptor subunit NR2B were significantly increased in comparison to the control group. An administration of LSPCs significantly attenuated these effects or diminished them completely.
The magnetic field exposure induced significant changes in the activation of the mitogen-activated protein kinase pathway. The ratios of phosphorylated ERK-1 to ERK-1 and of phosphorylated ERK-2 to ERK-2 were significantly decreased in the exposure group compared to the control group. These decreases were attenuated by a treatment with LSPCs. Furthermore, in the exposure group the protein expression level of ASK1 and the ratios of phosphorylated JNK-1 to JNK-1 and of phosphorylated JNK-2 to JNK-2 were significantly increased in comparison to the control group. An administration of LSPCs significantly attenuated these effects or diminished them completely.
In the hippocampus of mice from the exposure group, the ratio of phosphorylated CREB to CREB was significantly decreased when compared to the control group, while an administration of LSPCs attenuated this effect significantly.
The results suggest that extremely low frequency magnetic fields could alter the level of glutamate and influence the mitogen-activated protein kinase pathway in the hippocampus of mice. An administration of LSPCs could prevent those molecular changes and therefore the cognitive impairments reported in the previous examinations (Duan et al., 2013).

研究の種別:

研究助成

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