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

[長時間の35 GHzミリ波ばく露により誘発されたラット皮膚での遺伝子発現の変化] med./bio.

Gene Expression Changes in the Skin of Rats Induced by Prolonged 35 GHz Millimeter-Wave Exposure.

掲載誌: Radiat Res 2008; 169 (3): 288-300

この研究は、ミリ波(35GHz)への過剰ばく露に対する細胞および分子の反応を理解するために、ばく露後のSDラット87匹の皮膚遺伝子発現プロファイルおよび組織学的変化を調べた。実験は、擬似ばく露群、42度の環境熱ばく露群、およびミリ波ばく露群(35GHz、75mW/cm2)であった。ばく露群は、ばく露を開始してから結腸温が41-42度に達するまでばく露(約60分間)、環境熱ばく露群も同様の結腸温に達するまでばく露擬似ばく露群はミリ波が発生していないばく露装置内に60分間滞在させた。ばく露終了から3-6時間後および24-48時間後に採取したサンプルについて皮膚組織分析(36匹)、遺伝子発現分析(51匹)した。この結果、ミリ波ばく露群では、血管の好中球凝集、間質細胞の変性コラーゲン切断などが観察された:ミリ波ばく露群では、6時間後のサンプルでは56個、24時間後では58個の遺伝子に変化が観察された、などの所見を報告している。

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研究目的(著者による)

To study alterations in the gene expression profile and histology of skin (as location of the initial response to millimeter waves) of rats after exposure to 35 GHz radiofrequency.

詳細情報

Skin samples of 51 rats were collected at 6 and 24 h after exposure for microarray analysis. For histopathology analysis the skin of 36 was harvested from a separate group of rats at 3-6 h or 24-48 h after exposure.
Temperature control (42°C) was also performed.

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 35 GHz
ばく露時間: continuous for about 60 min

General information

Rats were subjected to sham exposure, to 42°C environmental heat, or to 35 GHz millimeter waves at 75 mW/cm². Animal exposures were performed as described previously [Millenbaugh et al., 2006] with some modifications. Preliminary experiments indicated that a colonic temperature of 41-42°C would provide a dose close to the maximum dose used in previous studies of MMW overexposure in this animal model [Millenbaugh et al., 2006; Ryan et al., 1997 and 1996].

ばく露1

主たる特性
周波数 35 GHz
タイプ
  • electromagnetic field
特性
  • far field
ばく露時間 continuous for about 60 min
ばく露装置
ばく露の発生源/構造
  • [Millenbaugh et al., 2006]
ばく露装置の詳細 Rats were placed on a custom-designed Styrofoam stand and were exposed to MMW until the colonic temperature reached 41-42°C which took a total of 58.6 ± 4.7 min including a 5-min pre-exposure control period.
Sham exposure A sham exposure was conducted.
Additional information During the 60-min sham exposure in the same setup, colonic temperatures were maintained at 37 ± 0.5°C using a water-perfused pad set at 37°C. Environmental heat control rats were exposed to warm air at 42°C in a custom-designed environmental chamber until the colonic temperature reached 41-42°C.
パラメータ
測定量 種別 Method Mass 備考
電力密度 75 mW/cm² - - - -

Reference articles

  • Millenbaugh NJ et al. (2006): [ミリ波エネルギーまたは環境熱にばく露されたラットの血圧と熱的反応の比較]
  • Ryan KL et al. (1997): [35 GHzミリ波加熱による循環器系への影響はない:慢性的な一酸化窒素精製の抑制効果]
  • Ryan KL et al. (1996): [35 GHzマイクロ波加熱による誘導される循環系への一酸化窒素は修飾するか]

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:
  • 感覚器
  • skin
調査の時期:
  • ばく露中
  • ばく露後

研究の主なアウトカム(著者による)

Changes were detected in 56 genes at 6 h and 58 genes at 24 h in the millimeter wave exposed rats. Genes associated with regulation of transcription, protein folding, oxidative stress, immune response, and tissue matrix turnover were affected at both times. At 24 h, more genes related to extracellular matrix structure and chemokine activity were altered. Up-regulation of some genes at 24 h was confirmed by RT-PCR.
In addition, the authors identified significant microscopic changes in skin induced by millimeter wave exposure and thus demonstrated that the detected changes in gene transcription may be associated with observable alterations in cell behavior and tissue structure.
The data are indicative of thermally induced injury to skin tissue. The observed responses to millimeter wave exposure differ significantly from those induced by warm air and from the sham exposure. This suggests that the differences in temperature gradients within the skin are the cause of the observed histological and molecular changes.

研究の種別:

研究助成

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