Study type: Medical/biological study (experimental study)

Effect of chronic intermittent exposure to AM radiofrequency field on responses to various types of noxious stimuli in growing rats. med./bio.

Published in: Electromagn Biol Med 2008; 27 (3): 266-276

Aim of study (acc. to author)

To study nociceptive responses to different noxious stimuli in growing rats exposed to a chronic intermittent radiofrequency field (73,5 MHz, 45 days).

Background/further details

Investigating the nociceptive status of an organism to a variety of noxious stimuli under radiofrequency exposure is of importance for setting exposure guidelines.
Male rats were assigned to a radiofrequency exposure group and to a control group. After chronic exposure, paw lick latency was first tested in unrestrained rats: (a) phasic pain, hot plate. After a rest of 4 h, rats were restrained for determination of threshold of pain: (b) electrical stimuli of varying current strength. On day two the tonic pain was studied: (c) injection of formalin into the paw.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 73.5 MHz
Modulation type: AM
Exposure duration: 2 h/day for 45 days

Exposure 1

Main characteristics
Frequency 73.5 MHz
Type
Exposure duration 2 h/day for 45 days
Modulation
Modulation type AM
Modulation frequency 15 Hz
Exposure setup
Exposure source
Setup 32 cm x 10 cm x 9 cm plexiglas cages
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 70.71 V/m - calculated - -
power density 1.33 mW/cm² - calculated - -
SAR 0.4 W/kg - calculated whole body -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

In radiofrequency exposed rats, the response to tonic pain was attenuated (c); the latency of tail flick was not affected (a); and the latency of response to hot plate decreased (a). The threshold of tail flick and simple vocalization were not affected while the threshold of vocalization after stimulus decreased (b).
The results suggest a decreased response to tonic pain indicating analgesia and a decreased threshold of vocalization after discharge indicating an exaggerated emotional response to painful stimuli. Radiofrequency fields differentially affect the mechanisms involved in the processing of various noxious stimuli.

Study character:

Study funded by

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