Study type: Medical/biological study (experimental study)

Suppressive effect of electromagnetic field on analgesic activity of tramadol in rats. med./bio.

Published in: Pol J Vet Sci 2012; 15 (1): 95-100

Aim of study (acc. to author)

To study the influence of microwave exposure on pain perception and anti-nociceptive activity of tramadol - analgetic effective in the treatment of moderate to severe acute and chronic pain states.

Background/further details

For each exposure, 40 animals were divided into four groups: 1) vehicle, 2) exposed to the electromagnetic field without medication, 3) drug (tramadol) application without exposure, and 4) drug application and electromagnetic field exposure (drug application immediately before exposure).
Paw withdrawal latency to a thermal stimulus was measured before and 30, 60 and 90 minutes after injections.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,500 MHz
Exposure duration: continuous for 15 min
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous for 15 min

General information

Animals were divided into four groups: 1) vehicle 2) exposed to the EMF without medication 3) receiving the drug without EMF 4) receiving the drug and exposed to EMF

Exposure 1

Main characteristics
Frequency 1,500 MHz
Type
Charakteristic
Exposure duration continuous for 15 min
Exposure setup
Exposure source
Chamber animals were placed in plexiglas cages
Setup cages were positioned 1 m from the EMF source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 90 V/m effective value - - -
magnetic field strength 0.24 A/m effective value - - -

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Charakteristic
Exposure duration continuous for 15 min
Modulation
Modulation type pulsed
Additional info

modulation similar to a GSM 1800 mobile phone

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 20 V/m effective value - - -
magnetic field strength 0.05 A/m effective value - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • after exposure

Main outcome of study (acc. to author)

The electromagnetic field exposure alone (at both 1500 and 1800 MHz frequencies) did not influence the pain perception threshold to the thermal stimulus. Tramadol significantly increased the paw withdrawal latency to the thermal stimulus in comparison to vehicle results at 30 and 60 minutes after injection. The electromagnetic field exposure of both frequencies (1500 MHz and 1800 MHz) significantly reduced the analgesic effect of tramadol at 30 minutes after injection. This effect disappeared at 60 minutes.

Study character:

Study funded by

Related articles