Study type: Medical/biological study (experimental study)

The effect of melatonin on morphological changes in liver induced by magnetic field exposure in rats. med./bio.

Published in: Okajimas Folia Anat Jpn 2002; 79 (1): 25-31

Aim of study (acc. to author)

To investigate the possible effects of melatonin on morphological changes in rat liver induced by 27.17 MHz radiofrequency exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 27.17 MHz
Exposure duration: repeated daily exposure (not specified) for 2 weeks
Exposure 2: 27.17 MHz
Exposure duration: repeated daily exposure (not specified) for 2 weeks

Exposure 1

Main characteristics
Frequency 27.17 MHz
Type
Exposure duration repeated daily exposure (not specified) for 2 weeks
Exposure setup
Exposure source
  • monopole
Chamber A wooden cage of 40 cm x 40 cm x 30 cm was used with a stainless steel ground plane of 1 m x 0.5 m placed under it.
Setup A monopole magnet whip antenna, about 30 cm high, was positioned vertically at half length of one side of the cage. The transmitter was a commercial CB hand-held portable transceiver of 4 W, 40 channels.
Additional info The rats were allocated to three groups: control, RF exposed, and RF exposed plus melatonin treated. The latter group received an i.p. injection of 4 mg/kg melatonin in ethanol (5%) in physiological saline (0.1 ml/100 g) daily after RF exposure. The others were injected with the vehicle only. Remark: It is not clear, why the authors talk about magnetic fields, instead of electromagnetic fields.
Parameters
Measurand Value Type Method Mass Remarks
power density 7.85 mW/cm² maximum measured - -
electric field strength 172.03 V/m effective value measured - -
electric field strength 243.28 V/m maximum measured - -
magnetic field strength 0.456 A/m effective value measured - -
magnetic field strength 0.645 A/m maximum measured - -

Exposure 2

Main characteristics
Frequency 27.17 MHz
Type
Exposure duration repeated daily exposure (not specified) for 2 weeks
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 2.314 mW/cm² minimum measured - -
electric field strength 93.4 V/m effective value measured - -
electric field strength 132.09 V/m maximum measured - -
magnetic field strength 0.247 A/m effective value measured - -
magnetic field strength 0.35 A/m maximum measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Morphological changes on parenchymal and stromal structures, necrosis and vacuolar degeneration were observed in animals exposed without melatonin treatment. Animals treated with melatonin (intraperitoneal injection, 4 mg/kg) were partially prevented from these effects caused by magnetic field (MF)exposure. Thus the findings suggest that melatonin by its capacity as a free radical scavenger has a minimal protective effect on 27 MHz MF induced changes on rat liver tissue.

Study character:

Study funded by

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