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

[150 kHz電磁界にばく露された慢性鉄過剰状態の若い成獣ラットの脳における酸化ストレスと適応反応阻害] med./bio.

Oxidative stress and prevention of the adaptive response to chronic iron overload in the brain of young adult rats exposed to a 150 kilohertz electromagnetic field.

掲載誌: Neuroscience 2011; 186: 39-47

【背景】鉄分の過剰は、いくつかの神経機能低下に基づく酸化ストレス誘発する可能性がある。その上、電気電子機器が放射する約105Hzまでの周波数の電磁界EMF)は鉄依存性経路を通してフリーラジカル生成を増強することが示唆されている。【目的】若い成獣ラットにおいて、鉄分の状態、EMFへのばく露、脳の酸化ストレスの関連の可能性を明らかにすること。【方法】慢性の塩分または鉄分過剰摂取後、および慢性の150KHzEMFばく露または擬似ばく露後、または鉄分の過剰摂取とEMF組み合わせばく露後における、前頭前皮質海馬線条体小脳組織切片を試料とした。これら脳の試料から、酸化ストレス誘導性の脂質過酸化および抗酸化酵素(スーパーオキサイドディスムターゼカタラーゼ)の活性を測定した。【結果】若い成獣ラットにおいて、鉄分過剰は、酸化ストレス誘導しなかったが、特に小脳および前頭前皮質における抗酸化防御を活性化した。対照的に、EMFばく露は、主に小脳において脂質過酸化を活性化したが、抗酸化防御に影響を与えなかった。EMFを鉄分過剰と共に与えた場合には、脂質過酸化はEMF単独の場合よりさらに増加したが、鉄分過剰単独で引き起こされた抗酸化防御の増加は見られなくなった。【結論】EMFばく露は、鉄分誘導性の酸化ストレスを阻害するための抗酸化防御を損なうことにより、若い成獣ラットに害を与えるかもしれないことが示唆された。

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研究目的(著者による)

To investigate whether a relationship exists between iron overload, exposure to electromagnetic fields and oxidative stress in the brain of young adult rats.

詳細情報

In 2009, Maaroufi et al. published their work about the influence of combined electromagnetic field exposure and iron overload as well as the treatments alone on spatial memory and learning in rats. To continue these experiments, the influence on molecular mechanisms, more precisely oxidative stress, were evaluated in the present study. Hence, the experimental setting is identical with Maaroufi et al. (2009).
The frequency of 150 kHz was chosen because intermediate frequencies have been poorly studied up to now, but are used in numerous electric devices such as induction cookers, metal detectors and welding devices.
Several groups of rats were examined (each group n=6-8): 1.) iron overload (daily injection of 3 mg FeSO4 per kg body weight during 21 consecutive days), 2.) control group (daily injection of saline solution), 3.) electromagnetic field exposure, 4.) electromagnetic field exposure + iron overload (daily injection of 3 mg FeSO4 per kg body weight during 21 consecutive days) and 5.) sham exposure.

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 150 kHz
ばく露時間: 1 hour per day for 21 consecutive days

ばく露1

主たる特性
周波数 150 kHz
タイプ
  • electromagnetic field
ばく露時間 1 hour per day for 21 consecutive days
ばく露装置
ばく露の発生源/構造
チャンバの詳細 cage (40 cm x 26 cm x 16 cm) with a plexiglas cover containing 6 rats was placed in the exposure chamber
ばく露装置の詳細 Helmholtz coils consisted of two parallel square based coils (50 cm x 35 cm), distance between the coils 24 cm, each coil was made of six turns (isolated 1.5 mm² copper wire) so that a 250 mA electric current was required to generate the required field; apparatus (containing the dipole antenna and the chamber) was placed in a temperature controlled (20°C), dimly lit room (1.7 m x 3.2 m) on a table
Sham exposure A sham exposure was conducted.
パラメータ
測定量 種別 Method Mass 備考
磁界強度 5 A/m minimum 測定値 - -
磁界強度 5.75 A/m maximum 測定値 - -
磁束密度 6.25 µT - 測定値 - -

Reference articles

  • Maaroufi K et al. (2009): [長期にわたる鉄過剰と低周波電磁界ばく露が若いラットの空間学習と記憶に及ぼす効果]

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:
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 cerebellum, iron overload led to a significantly increased enzyme activity of the superoxide dismutase and the catalase compared to the control group with saline administration, while no influence was observed of iron overload on the lipid peroxidation.
On the contrary, electromagnetic field exposure significantly increased the lipid peroxidation in the cerebellum compared to the sham exposure group, but did not influence the antioxidant enzyme activities. The combination of electromagnetic field exposure and iron overload (group 4) led to a further increase of the lipid peroxidation: Here, the lipid peroxidation was significantly increased in the cerebellum in comparison to the sham exposure group and the electromagnetic field exposure group (group 3).
No significant differences between the groups were observed in the prefrontal cortex, striatum and hippocampus.

研究の種別:

研究助成

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