Study type: Medical/biological study (experimental study)

Effect of magnetic fields on antioxidative defense and fitness-related traits of Baculum extradentatum (insecta, phasmatodea). med./bio.

Published in: Bioelectromagnetics 2012; 33 (3): 265-273

Aim of study (acc. to author)

To study whether a static magnetic field or an alternating magnetic field affects the activity of antioxidants in walking stick nymphs (Baculum extradentatum).
Also of interest were the effects of these magnetic fields on egg mortality, embryonic development and mass of the hatched nymphs

Background/further details

Three groups were analyzed: a control group and two exposure groups. The total number of eggs examined in each group was: control group (135 eggs); "static magnetic field group" (115 eggs); and "alternating magnetic field group" (102 eggs). In each experimental group all nymphs from a single female were pooled, creating 10 pools of 6-10 individuals per group.

Endpoint

Exposure

Exposure Parameters
Exposure 1:
Exposure duration: from oviposition until completion of the embryonic development
Exposure 2: 50 Hz
Exposure duration: from oviposition until completion of the embryonic development

Exposure 1

Main characteristics
Frequency
Type
Exposure duration from oviposition until completion of the embryonic development
Exposure setup
Exposure source
Setup permanent double-U-shaped magnet with a pole area of 25.6 cm² and a 7.2 cm gap between the poles; upper half of the magnet with two north poles at its ends and a south pole in the middle; lower part of the magnet with two south poles at its ends and a north pole in the middle; eggs placed in 3.5 cm Petri dishes between the poles at the ends of the magnet
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 50 mT - measured - -
magnetic flux density 320 mT maximum measured - at the poles

Exposure 2

Main characteristics
Frequency 50 Hz
Type
Exposure duration from oviposition until completion of the embryonic development
Exposure setup
Exposure source
Setup electromagnet consisting of three coil pairs placed around a regular laminated transformer core; each coil made of 84 turns of 1 mm diameter copper wire; surface of the magnet's poles = 44.6 cm²; space between the poles = 7 cm; eggs placed in 3.5 cm Petri dishes in the central pole area
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 6 mT average over time measured - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The exposure to the alternating magnetic field or the static magnetic field increased the superoxide dismutase enzyme activity in the Annam walking stick nymphs. The catalase enzyme activity tended to increase (but statistically not significant) upon exposure to the static magnetic field compared to the control group. The activity of this enzyme showed a significant increase in the "alternating magnetic field group" compared to the control group. No significant effect of both magnetic fields was found for the total glutathione content.
There were no significant differences in egg mortality between the control and experimental groups. Regarding the time of development, a significant effect of both magnetic fields was found: The time of development was reduced. Differences in the time of development between both magnetic field groups were also significant: The development in the "alternating magnetic field group" in comparison to the "static magnetic field group" was shortened. There were no significant differences in the average mass of the nymphs hatched among all groups.
In conclusion: In the Annam walking stick a static magnetic field and an alternating magnetic field were able to change the antioxidative defense strategy and accelerate the metamorphosis processes (i.e. shorten the embryonic development) .

Study character:

Study funded by

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