Medical/biological study (experimental study)

Weak extremely-low-frequency magnetic field-induced regeneration anomalies in the planarian Dugesia tigrina med./bio.

By: Jenrow KA, Smith CH, Liboff AR

Published in: Bioelectromagnetics 1996; 17 (6): 467-474

Aim of study (acc. to editor)

To study the effect of weak extremely low frequency magnetic fields on regeneration anomalies in the planarian Dugesia tigrina.

Background/further details

The authors recently reported (publication 2870) that cephalic regeneration in the planarian Dugesia tigrina was significantly delayed in populations exposed continuously to combined parallel DC (78.4 µT) and AC (60 Hz, 10µT) magnetic fields. This effect was consistent with hypotheses suggesting an underlying resonance phenomenon.
The turbellarian flatworm Dugesia tigrina is of particular research importance since it embodies a large number of stem cells in its connective tissue which, after injuries or lesions, can differentiate into new nerves, muscles, sensory organs, and other tissues. Due to its regeneration ability the planarian plays an important role in regeneration research.
Transverse lesions were made immediately posterior to the auricles (before exposure).

Endpoint

morphol./histopathol. changes: cephalic regeneration/regeneration anomalies (after transverse lesion)

Exposure

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: 12 days continuous exposure, except approx. 1 hour each day for observations, calibration and measurements Faraday control	magnetic flux density: 0.01 µT cf. remarks (vertical DC field +/- 0.1 µT) magnetic flux density: 0.01 µT cf. remarks (horizontal DC field +/- 0.05 µT) magnetic flux density: 1 µT peak value (AC field) magnetic flux density: 10 µT peak value (AC field) magnetic flux density: 40 µT peak value (AC field) magnetic flux density: 51.1 µT peak value (AC field) magnetic flux density: 78.4 µT peak value (AC field)
Exposure 2: 60 Hz Exposure duration: 12 days continuous Calcium Resonance	magnetic flux density: 0.01 µT cf. remarks (vertical DC field +/- 0.1 µT) magnetic flux density: 1 µT peak value (AC field) magnetic flux density: 10 µT peak value (AC field) magnetic flux density: 40 µT peak value (AC field) magnetic flux density: 78.4 µT peak value (AC field) magnetic flux density: 78.42 µT cf. remarks (horizontal DC field +/- 0.18 µT)
Exposure 3: 60 Hz Exposure duration: 12 days continuous Potassium resonance	magnetic flux density: 0.05 µT cf. remarks (vertical DC field +/- 0.05 µT) magnetic flux density: 51.13 µT cf. remarks (horizontal DC field +/- 0.12 µT) magnetic flux density: 51.1 µT peak value (AC field)
Exposure 4: DC/static Exposure duration: 12 days continuous Ambient	magnetic flux density: 53.5 µT cf. remarks (vertical DC field +/- 0.01 µT) magnetic flux density: 18.2 µT cf. remarks (horizontal DC field +/- 0.01 µT)
Exposure 5: DC/static Exposure duration: 12 days continuous Passive control	magnetic flux density: 0.01 µT cf. remarks (vertical DC field +/- 0.1 µT) magnetic flux density: 18.2 µT cf. remarks (horizontal DC field +/- 0.01 µT)

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	12 days continuous exposure, except approx. 1 hour each day for observations, calibration and measurements
Additional info	Faraday control

Exposure setup

Exposure source	Helmholtz coils solenoid
Setup	3 identical solenoids, each 24 cm apart and horizontally aligned, were centered in a triple-axis Helmholtz coil system; an AC signal was fed to the first solenoid that was connected in series to a matching set of windings in the second solenoid; an additional DC signal was fed to a second set of windings of these solenoids; a third solenoid was placed between these two
Additional info	in the first coil the resulting field consisted only of the AC component; in the second coil resulted a combination of AC and DC magnetic field; in the third coil the horizontal component of the geomagnetic field and a residual AC field of 0,2 µT existed

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.01 µT	cf. remarks	measured	-	vertical DC field +/- 0.1 µT
magnetic flux density	0.01 µT	cf. remarks	measured	-	horizontal DC field +/- 0.05 µT
magnetic flux density	1 µT	peak value	measured	-	AC field
magnetic flux density	10 µT	peak value	measured	-	AC field
magnetic flux density	40 µT	peak value	measured	-	AC field
magnetic flux density	51.1 µT	peak value	measured	-	AC field
magnetic flux density	78.4 µT	peak value	measured	-	AC field

Exposure 2

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	12 days continuous
Additional info	Calcium Resonance

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.01 µT	cf. remarks	measured	-	vertical DC field +/- 0.1 µT
magnetic flux density	1 µT	peak value	measured	-	AC field
magnetic flux density	10 µT	peak value	measured	-	AC field
magnetic flux density	40 µT	peak value	measured	-	AC field
magnetic flux density	78.4 µT	peak value	measured	-	AC field
magnetic flux density	78.42 µT	cf. remarks	measured	-	horizontal DC field +/- 0.18 µT

Exposure 3

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	12 days continuous
Additional info	Potassium resonance

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.05 µT	cf. remarks	measured	-	vertical DC field +/- 0.05 µT
magnetic flux density	51.13 µT	cf. remarks	measured	-	horizontal DC field +/- 0.12 µT
magnetic flux density	51.1 µT	peak value	measured	-	AC field

Exposure 4

Main characteristics

Frequency	DC/static
Type	magnetic field
Waveform	sinusoidal
Exposure duration	12 days continuous
Additional info	Ambient

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	53.5 µT	cf. remarks	measured	-	vertical DC field +/- 0.01 µT
magnetic flux density	18.2 µT	cf. remarks	measured	-	horizontal DC field +/- 0.01 µT

Exposure 5

Main characteristics

Frequency	DC/static
Type	magnetic field
Exposure duration	12 days continuous
Additional info	Passive control

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.01 µT	cf. remarks	measured	-	vertical DC field +/- 0.1 µT
magnetic flux density	18.2 µT	cf. remarks	measured	-	horizontal DC field +/- 0.01 µT

Reference articles

Jenrow KA et al. (1995): Weak extremely-low-frequency magnetic fields and regeneration in the planarian Dugesia tigrina

Exposed system:

invertebrate
turbellarian, flatworm/Dugesia tigrina
whole body

Methods Endpoint/measurement parameters/methodology

morphol./histopathol. changes: extent of cephalic regeneration/regeneration anomalies (daily observation; normal regeneration, abnormal morphogenesis, disaggregation)

Investigated system:

investigation on living organism

Investigated organ system:

head

Time of investigation:

during exposure

Main outcome of study (acc. to author)

The data showed that weak extremely low frequency magnetic fields can significantly increase the incidence of regeneration anomalies in cephalically regenerating planaria. The magnitude of the response increased as a function of AC field intensity. Similar to regeneration rate effects, the incidence of regeneration anomalies was specifically dependent upon the planaria possessing a fixed orientation with respect to the applied magnetic field vectors.
The results suggest that cephalic regeneration in the planarian represents an excellent model system for investigating teratogenic effects of weak extremely low frequency magnetic fields.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

not stated/no funding

Goodman R et al. (2009): Extremely low frequency electromagnetic fields activate the ERK cascade, increase hsp70 protein levels and promote regeneration in Planaria
Novikov VV et al. (2008): Effect of weak static and low-frequency alternating magnetic fields on the fission and regeneration of the planarian dugesia (Girardia) tigrina
Shams Lahijani M et al. (2007): Light and electron microscope studies of effects of 50 Hz electromagnetic fields on preincubated chick embryo
Parivar K et al. (2006): Organ culture studies on the development of mouse embryo limb buds under EMF influence
Kuzna-Grygiel W et al. (2005): Effect of electric power network frequency magnetic field on embryonic development of Ascaris suum (Nematoda)
Shams Lahijani M et al. (2004): Development of preincubated chicken eggs following exposure to 50 Hz electromagnetic fields with 1.33-7.32 mT flux densities
Juutilainen J (2003): Developmental effects of extremely low frequency electric and magnetic fields
Levin M (2003): Bioelectromagnetics in morphogenesis
Huuskonen H et al. (2001): Development of preimplantation mouse embryos after exposure to a 50 Hz magnetic field in vitro
Shams Lahijani M et al. (2000): Teratogenic effects on morphology and skeletal structure of chick embryos after exposure to 50 Hz sinusoidal electromagnetic fields
Huuskonen H et al. (1998): Teratogenic and reproductive effects of low-frequency magnetic fields
Huuskonen H et al. (1998): Effects of low-frequency magnetic fields on fetal development in CBA/Ca mice
Jenrow KA et al. (1995): Weak extremely-low-frequency magnetic fields and regeneration in the planarian Dugesia tigrina
Ubeda A et al. (1994): Chick embryo development can be irreversibly altered by early exposure to weak extremely-low-frequency magnetic fields
Frölen H et al. (1993): Effects of pulsed magnetic fields on the developing mouse embryo (incl. Erratum)
Huuskonen H et al. (1993): Effects of low-frequency magnetic fields on fetal development in rats
Juutilainen J (1991): Effects of low-frequency magnetic fields on embryonic development and pregnancy
Berman E et al. (1990): Development of chicken embryos in a pulsed magnetic field
Maffeo S et al. (1988): Weak low frequency electromagnetic fields and chick embryogenesis: failure to reproduce positive findings
Juutilainen J et al. (1987): Relationship between field strength and abnormal development in chick embryos exposed to 50 Hz magnetic fields
Juutilainen J et al. (1986): Effects of 100-Hz magnetic fields with various waveforms on the development of chick embryos
Leal J et al. (1982): Embryonic Development And Weak Changes Of The Geomagnetic Field
Delgado JM et al. (1982): Embryological changes induced by weak, extremely low frequency electromagnetic fields

Weak extremely-low-frequency magnetic field-induced regeneration anomalies in the planarian Dugesia tigrina med./bio.

Aim of study (acc. to editor)

Background/further details

Endpoint

Exposure

Exposure 1

Main characteristics

Exposure setup

Parameters

Exposure 2

Main characteristics

Exposure setup

Parameters

Exposure 3

Main characteristics

Exposure setup

Parameters

Exposure 4

Main characteristics

Exposure setup

Parameters

Exposure 5

Main characteristics

Exposure setup

Parameters

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

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