Medical/biological study (experimental study)

Effects of Long-term Exposure of Extremely Low Frequency Magnetic Field on Oxidative/Nitrosative Stress in Rat Liver med./bio.

By: Erdal N, Gurgul S, Tamer L, Ayaz L

Published in: J Radiat Res 2008; 49 (2): 181-187

Aim of study (acc. to author)

This study was performed to examine the long-term effects of 50 Hz, 1 mT magnetic field on oxidative stress and nitrosative stress in liver tissues of rats.

Background/further details

Altogether thirty-two (16 male, 181 +/- 10 g body weight and 16 female, 178 +/- 15 g body weight ), eight week-old rats were used.

Endpoint

cell function: oxidative stress and nitrosative stress

Exposure

- 50/60 Hz
- magnetic field

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: continuous for 4 h/day on 45 days	magnetic flux density: 1 mT (+/- 0.05 mT)

General information

rats were divided into four groups: i) female exposed ii) female sham exposed iii) male exposed iv) male sham exposed

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	continuous for 4 h/day on 45 days

Exposure setup

Exposure source	Helmholtz coils
Setup	pair of circular Helmholtz coils with a diameter of 42.75 cm, 21.375 cm apart, with 160 turns of 2.2 mm insulated copper wire, placed in a 70 cm x 65 cm x 65 cm Faraday cage; rats placed between the coils in a 26 cm x 17 cm x 13 cm polycarbonate cage mounted on electrically grounded metal nets
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	1 mT	-	measured	-	+/- 0.05 mT

Exposed system:

animal
rat/Wistar albino
whole body

Methods Endpoint/measurement parameters/methodology

cell function: oxidative stress: malondialdehyde level (thiobarbituric acid reaction), nitrosative stress (stress due to aggressive oxygen nitrogen bonds): nitrotyrosine level (high performance liquid chromatography)

Investigated system:

isolated bio./chem. substance
tissue homogenate

Investigated organ system:

liver

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Concerning malondialdehyde levels, there were no significant differences between the control groups and magnetic field exposure groups. However, female rats exposed to magnetic field showed significantly increased nitrotyrosine levels. This effect was not seen in exposed male rats.
These results suggest that the long-term extremely low frequency magnetic field exposure may enhance the oxidative/nitrosative stress in liver tissue of the female rats and could have a negative effect on cellular proteins rather than lipids by enhancing nitrotyrosine formation.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

not stated/no funding

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