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The influence of static magnetic fields on mechanosensitive ion channel activity in artificial liposomes.
Hughes S, El Haj AJ, Dobson J, Martinac B.
Medical Research Unit, Institute of Science and Technology in Medicine,
Keele University, Thornburrow Drive, Hartshill, Stoke-on-Trent,
Staffordshire, ST4 7QB, UK, findstevenhughes@hotmail.com.
The influence of static magnetic fields (SMFs) on the activity of
recombinant mechanosensitive ion channels (the bacterial
mechanosensitive ion channel of large conductance-MscL) following
reconstitution into artificial liposomes has been investigated.
Preliminary findings suggest that exposure to 80-mT SMFs does not induce
spontaneous MscL activation in the absence of mechanical stimulation.
However, SMFs do appear to influence the open probability and single
channel kinetics of MscL exposed to negative pipette pressure. Typical
responses include an overall reduction in channel activity or an
increased likelihood of channels becoming "trapped open" in
sub-conducting states following exposure to SMFs. There is a delay in
the onset of this effect and it is maintained throughout exposure.
Generally, channel activity showed slow or limited recovery following
removal of the magnetic field and responses to the magnetic were often
reduced or abolished upon subsequent exposures. Pre-exposure of the
liposomes to SMFs resulted in reduced sensitivity of MscL to negative
pipette pressure, with higher pressures required to activate the
channels. Although the mechanisms of this effect are not clear, our
initial observations appear to support previous work showing that the
effects of SMFs on ion channels may be mediated by changes in membrane
properties due to anisotropic diamagnetism of lipid molecules.
PMID: 15959773 [PubMed - in process]
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Magnetic airway implants for the treatment of obstructive sleep apnea syndrome.
Nelson LM, Boucher RP, Stevens SS.
Otolaryngology-Head and Neck Surgery Clinic, San Jose, CA, USA. LNelson580@aol.com
OBJECTIVE: To evaluate repelling magnetic implants to treat obstructive sleep apnea (OSA) using a canine model.
STUDY DESIGN AND SETTING: Magnetic forces equivalent to
effective CPAP were estimated with benchtop studies. An acute canine
model was used to simulate pharyngeal collapse. Tolerance, safety, and
stability of the implants were evaluated in a chronic series of 10 dogs
observed over 6 months.
RESULTS: Equivalence to CPAP (10-12 cm H(2)O) was achieved
with low-force (<10 g/cm length), light (approximately 2 gram)
implants. Magnetic implants prevented airway collapse in the acute
canine. Normal behavior, swallowing, and oral intake were noted in the
chronic canine over 6 months. Implant extrusion was 10%. Histology
showed fibrous encapsulation without chronic inflammation.
CONCLUSIONS: Repelling magnets successfully maintained a patent airway and were well tolerated in the canine.
SIGNIFICANCE: Repelling magnets could represent an implantable alternative to CPAP if human studies reveal similar findings.
PMID: 16360520 [PubMed - indexed for MEDLINE]
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On the modulation effect of pulsing and static magnetic fields and mechanical vibrations on barley seed hydration.
Amyan A, Ayrapetyan S.
UNESCO Chair-Life Sciences International Postgraduate Educational Center, Yerevan, 375040 Armenia.
The changes of wet and dry weights of barley seed in different
periods of swelling were studied in seeds treated with Extremely Low
Frequency Electromagnetic Fields (ELF EMF), Static Magnetic Fields (SMF)
and Mechanical Vibrations (MV) in cold (4 degrees C) and warm (20
degrees C) distilled water as well as in seeds non-treated (control).
The metabolic dependent seed hydration, dry weight loss and water
binding in seed were modulated by preliminary EMF, SMF and MV-induced
treatment of distilled water. The specific electrical conductivity (SEC)
of control and treated distilled water was measured before the seed
incubation. Frequency and intensity "windows" (i.e. range of frequency
or intensity) for the effect of EMF, MV and SMF (correspondingly) on
seed hydration, solubility and water binding in seed were studied. These
"windows" were different in various phases of seed swelling. It is
suggested that water structure modification is the result of valence
angle changes (SMF and EMF) and dipole molecules vibration (EMF and MV)
has different effects on the process of hydration, solubility and water
binding in seed. These results are important from the point of
understanding the mechanisms of the biological effect of EMF, as well as
from the point of agriculture.
PMID: 15789974 [PubMed - indexed for MEDLINE]
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Transcriptional regulation of neuronal genes and its effect on
neural functions: gene expression in response to static magnetism in
cultured rat hippocampal neurons.
Hirai T, Yoneda Y.
Laboratory of Molecular Pharmacology, Division of Pharmaceutical
Sciences, Kanazawa University Graduate School of Natural Science and
Technology, Ishikawa, Japan.
We have previously shown a marked but transient increase in DNA
binding of the nuclear transcription factor activator protein-1 after
brief exposure to static magnetic fields in cultured rat hippocampal
neurons, suggesting that exposure to static magnetism would lead to
long-term consolidation as well as amplification of different functional
alterations through modulation of de novo protein synthesis at the
level of gene transcription in the hippocampus. Hippocampal neurons were
cultured under sustained exposure to static magnetic fields at 100 mT,
followed by extraction of total RNA for differential display (DD)
analysis using random primers. The first and the second DD polymerase
chain reaction similarly showed the downregulation of particular genes
in response to sustained magnetism. Nucleotide sequence analysis
followed by BLASTN homology searching revealed high homology of these 2
DD-PCR products to the 3' non-coding regions of the mouse basic
helix-loop-helix transcription factor ALF1 and that of histone H3.3A,
respectively. On Northern blot analysis using the 2 cloned
differentially expressed fragments labeled with [alpha-(32)P]dCTP by the
random primer method, a marked decrease was seen in expression of mRNA
for ALF1 and histone H3.3A in hippocampal neurons cultured under
sustained exposure to static magnetic fields at 100 mT. It thus appears
that static magnetism may modulate cellular integrity and functionality
through expression of a variety of responsive genes required for gene
transcription and translation, proliferation, differentiation,
maturation, survival, and so on in cultured rat hippocampal neurons.
PMID: 16020920 [PubMed - indexed for MEDLINE]
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Static magnetic field influence on rat brain function detected by heart rate monitoring.
Veliks V, Ceihnere E, Svikis I, Aivars J.
Faculty of Biology, University of Latvia, Riga, Latvia. viktorvel@one.lv
The aim of the present study was to identify the effects of a static
magnetic field (SMF) on rat brain structures that control autonomic
functions, specifically heart rate and heart rhythmicity. The
experiments were carried out on 44 male Wistar rats under
ketamine-xylazine anesthesia. SMF was induced using samarium-cobalt
fused magnets (20 x 20 x 10 mm in size) placed bitemporally. Magnetic
induction intensity was 100 mT on the surface of the head. Duration of
magnetic field application was 15 min. An electrocardiogram was recorded
from limb lead II, and both heart rate (average duration of cardiac
cycles) and heart rhythmicity were analyzed before and after SMF
application. SMF evoked changes in both heart rate and rhythm in 80% of
the animals; the predominant effects were bradycardia and disappearance
of respiratory sinus arrhythmia. However, the effectiveness of SMF in
large measure depends on both functional peculiarities and functional
activities of brain autonomic centers. Copyright 2004 Wiley-Liss, Inc.
PMID: 15042630 [PubMed - indexed for MEDLINE]
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Static magnetic fields enhancement of Saccharomyces cerevisae ethanolic fermentation.
da Motta MA, Muniz JB, Schuler A, Da Motta M.
Departments of Biophysics and Chemical Engineering, University Federal
de Pernambuco, Recife PE 50960.870, Brazil. motta@ufpe.br
Magnetic effects induced in ethanolic fermentation by Saccharomyces
cerevisiae strain DAUFPE-1012 were studied during a 24 h exposure to 220
mT steady magnetic fields (SMF) at 23 +/- 1 degrees C, produced by
NdFeB rod magnets. The magnets were attached diametrically opposed (N to
S) to a cylindrical tube reactor. The biomass growth in the reactor
culture media (yeast extract + glucose 2%) during 24 h was monitored by
measurements of optical density, which was correlated to cell dry
weight. Ethanol concentration and glucose level were measured every 2 h.
The pH of the culture media was maintained between 4 and 5. As a
result, biomass (g/L) increased 2.5-fold and ethanol concentration
3.4-fold in magnetized cultures (n = 8) as compared with SMF nonexposed
cultures (n = 8). Glucose consumption was higher in magnetized cultures,
which correlated to the ethanol yield.
PMID: 14763869 [PubMed - indexed for MEDLINE]
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Quantitative analysis of adherent cell orientation influenced by strong magnetic fields.
Umeno A, Ueno S.
Department of Electronic Engineering, Graduate School of Engineering,
University of Tokyo, Tokyo, Japan. akinori@iis.u-tokyo.ac.jp
This paper examines the effect of strong magnetic fields on adherent
cells. Smooth muscle cells, cultured in 8- or 14-T superconducting
magnets for three days, exhibited orientational order parallel to the
magnetic field direction. To discuss the process and the mechanism of
the orientation, the orientational characteristic of the cell culture
was investigated with quantitative measurements: an orientational order
parameter and the Fourier transform (FT) analysis. The orientational
order parameter indicates the degree of orientation. The value of the
parameter was estimated with the FT of microscopic images. The cells
cultured under stronger static magnetic fields exhibited stronger
ordering, while they showed weaker ordering in the control when they
were cultured under a strong magnetic gradient force of 400 T2/m. The
ordering was enhanced under uniform strong magnetic fields, while it was
not affected or was suppressed by the strong gradient force. We suggest
that the cells organize themselves to minimize their diamagnetic
torsion stresses, which can be induced in the uniform magnetic fields by
the membrane's diamagnetic anisotropy.
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Health hazards and electromagnetic fields.
Saunders T.
tom@thomassaunders.net
Biological rhythms, physical wellbeing and mental states are
dependent on our electrical brainwave system interacting with the
extremely weak electromagnetic fields generated by the Earth's telluric
and Cosmic radiations. In a single generation, since the evolution of
humankind over millions of years, we are exposed to a wide range of
powerful, artificially generated electromagnetic radiation which
adversely affects the subtle balance in nature's energy fields and has
become the source of so-called 'diseases of civilization'. This also
includes electromagnetic sensitivity. Generally, there is a lack of
awareness and understanding of the impact electromagnetic fields can
have upon health and wellbeing.Our ancestors were acutely aware that
certain locations, were perceived to have a positive energy field which
was beneficial to health and vitality. Over time, these areas are now
referred to as sacred sites for spiritual ceremony and as healing
centres. In contrast, there are other geographical locations that can
have a negative effect upon health and these are known as geopathic
stress zones. It is believed that such zones can interfere with the
brain's normal function that inhibits the release of melatonin and other
endocrine secretions needed to replenish the immune system. Geopathic
stress can affect animals and plant life as well as human beings and
significantly contributes to sick building syndrome (SBS). Whilst there
is an increasing body of opinion amongst eminent researchers and
scientists who are addressing these issues, the establishment
professions are slow to change. However, very gradually, modern
allopathic medicine and attitudes are beginning to recognise the
extraordinary wisdom and efficacy of ancient traditions such as
acupuncture, light, colour and other therapies based on the
understanding and treatment of the interaction of a person's
electromagnetic subtle body and the immediate environment. These and
many other 'complementary' therapies may soon become mainstream medical
practice. In the meantime, we can help ourselves by learning how to
detect the hazards and daily practice prudent avoidance.
Complement Ther Nurs Midwifery. 2003 Nov;9(4):191-7.
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The physical nature of life.
Kalmijn AJ, Gonzalez IF, McClune MC.
The Faraday Laboratory, Physical Oceanography Research Division,
Scripps Institution of Oceanography, La Jolla, University of California,
San Diego, CA 92093-0220, USA. adjkalmijn@ucsd.edu
Life evolved from the primeval world of physics. Sensory systems
inform animals of the natural environment, enabling them to conduct
responsively. The discovery of weak, DC bioelectric fields in the
vicinity of aquatic organisms and the role they play in guiding sharks
and rays to their prey have led to the recognition of fundamental,
hitherto less well known, physical aspects of sensory biology. The
infrared cybernetic algorithm of electric-field orientation in sharks
and rays is highly effective and extremely robust. In orienting to the
weak DC electric fields of ocean currents and to the earth's magnetic
field, sharks and rays unwittingly practise the motional-electric
principles that Einstein had in mind when he introduced the special
theory of relativity. At the sense-organ, receptor-membrane, and
ion-channel levels, the elasmobranch ampullae of Lorenzini operate on
the basis of graded positive feedback driven by negative conductance,
supposedly employing voltage-sensitive ion channels as the active,
excitable elements. The electric sense of sharks and rays presents an
exquisite implementation of the very biophysical principles that also
govern the graded, much richer than all-or-none, integrative brain
processes of animal and man.
J Physiol Paris. 2002 Sep-Dec; 96(5-6): 355-62.
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A subterranean mammal uses the magnetic compass for path integration.
Kimchi T, Etienne AS, Terkel J.
*Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
Path integration allows animals to navigate without landmarks by
continuously processing signals generated through locomotion. Insects
such as bees and ants have evolved an accurate path integration system,
assessing and coding rotations with the help of a general directional
reference, the sun azimuth. In mammals, by contrast, this process can
take place through purely idiothetic (mainly proprioceptive and
vestibular) signals. However, without any stable external reference for
measuring direction, path integration is highly affected by cumulative
errors and thus has been considered so far as valid only for
short-distance navigation. Here we show through two path integration
experiments (homing and shortcut finding) that the blind mole rat
assesses direction both through internal signals and by estimating its
heading in relation to the earth's magnetic field. Further, it is shown
that the greater the circumvolution and length of the traveled path, the
more the animal relies on the geomagnetic field. This path integration
system strongly reduces the accumulation of errors due to inaccuracies
in the estimation of rotations and thus allows the mole rat to navigate
efficiently in darkness, without the help of any landmark, over both
short and long distances.
Proc Natl Acad Sci U S A. 2004 Jan 19 [Epub ahead of print]
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Somaticoautonomic functions of rabbits exposed to an ultrahigh-frequency electromagnetic field at acupuncture points.
Vagin IuE, Vagina LV, Batsiuro SG.
The action of electromagnetic field of ultrahigh frequency with power
from 1 to 1000 mwt and acupuncture on the functional state of rabbits
under the tooth pulp irritation conditions has been investigated. The
action on the points has been established to be accompanied by decrease
of the rythm breathing irregularity and motion of animals jaws. The most
effectiveness during the action of the field has been registered with
power 1-20 mwt that corresponds to the effectiveness of acupuncture.
However during the action of the field the frequency of breathing does
not change while during acupuncture it increases. This fact points out
the differences of the mechanism of normalized effect of these species
influence on acupuncture points. The point of view concerning the
invariable information action of fields upon the points and the system
of points as constantly acting communication channel between an organism
and the environment is under discussion.
Nauchnye Doki Vyss Shkoly Biol Nauki. 1985;(10):50-5.
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Effect of static magnetic field on some enzymes activities in rats.
Gorczynska E, Wegrzynowicz R.
Department of Biochemistry, Agriculture Academy, Szczecin, Poland.
The magnetic field of 0.008 T and 0.15 T inductions influence lasting
7 weeks (7 days a week), 1 h daily determines the increase of the
activity of cytoplasmatic enzymes (glutamic pyruvic transaminase,
glutamic oxalacetic transaminase, lactic dehydrogenase), the decrease of
cholinesterase activity and the growth of alkaline phosphatase activity
in the plasma of the examined animals. The observed changes were
reversible. 2 months after the exposure had been stopped, the tested
parameters were back to normal.
J Hyg Epidemiol Microbiol Immunol. 1989;33(2):149-55.
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Skin temperature changes induced by strong static magnetic field exposure.
Ichioka S, Minegishi M, Iwasaka M, Shibata M, Nakatsuka T, Ando J, Ueno S.
Department of Plastic and Reconstructive Surgery, Saitama Medical School, Saitama, Japan. ichioka-stm@umin.ac.jp
High intensity static magnetic fields, when applied to the whole body
of the anesthetized rat, have previously been reported to decrease skin
temperature. The hypothesis of the present study was that in
diamagnetic water, molecules in the air play significant roles in the
mechanism of skin temperature decrease. We used a horizontal cylindrical
superconducting magnet. The magnet produced 8 T at its center. A
thermistor probe was inserted in a subcutaneous pocket of the
anesthetized rats to measure skin temperature. Animals (n=10) were
placed in an open plastic holder in which the ambient air was free to
move in any direction (group I). Animals (n=10) were placed in a closed
holder in which the air circulation toward the direction of weak
magnetic field was restricted (group II). Each holder was connected to a
hydrometer to measure humidity around the animal in the holder. The
data acquisition phase consisted of a 5 min baseline interval, followed
by inserting the animal together with the holder into the center of the
magnet bore for a 5 min exposure and a 5 min postexposure period outside
the bore. In group I, skin temperature and humidity around the animal
significantly decreased during exposure, followed by recovery after
exposure. In group II, skin temperature and humidity did not decrease
during the measurement. The skin temperature decrease was closely
related to the decrease in humidity around the body of the animal in the
holder, and the changes were completely blocked by restricting the air
circulation in the direction of the bore entrance. Possible mechanisms
responsible for the decrease in skin temperature may be associated with
magnetically induced movement of water vapor at the skin surface,
leading to skin temperature decrease. Copyright 2003 Wiley-Liss, Inc.
Bioelectromagnetics. 2003 Sep;24(6):380-6.
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Vortex or whorl formation of cultured human corneal epithelial cells induced by magnetic fields.
Dua HS, Singh A, Gomes JA, Laibson PR, Donoso LA, Tyagi S.
Department of Ophthalmology, Queen's Medical Centre, University Hospital, Nottingham, UK.
The terms 'vortex keratopathy' and 'hurricane keratopathy' describe
two similar conditions affecting the corneal surface. In the former, a
vortex or whorl pattern is seen on the corneal surface and is due to the
deposition of substances such as pigment, iron or drugs in the
epithelial cells. In the latter, a similar pattern is presented by
migrating epithelial cells but, unlike the former, the pattern is
rendered more visible by fluorescein staining. Both represent the
migratory pattern of normal epithelial cells which is otherwise not
visible due to the slow rate of epithelial turnover and migration. The
whorl pattern has a clockwise predisposition in the majority of cases
and is hypothesised to be due to the influence of ocular
electro-magnetic fields on the migrating epithelial cells. In this study
we tested in vitro the effect of static magnetic fields on corneal
epithelial cells. We were able to reproduce dramatic vortex or whorl
patterns in response to magnetic fields, but without preferential
migration towards the North or South Pole.
Eye. 1996;10 ( Pt 4):447-50.
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Observation of cholesterol nucleation in a magnetic field.
Sandarac NM, Ashok M, Kalkura SN.
Crystal Growth Centre, Anna University, Chennai-600 025, India.
The in vitro studies on the nucleation, growth and other fundamental
aspects of cholesterol crystallization have received considerable
attention, as it plays a vital role in the formation of atheroclerotic
plaques and gallbladder stones. The cholesterol was crystallized in
methanol, ethanol, acetone and isopropanol at the physiological
temperature of 37 degrees C in the presence and absence of a low static
magnetic field at 0.1 T. The presence of magnetic field was found to
have a significant effect on the metastable zone width and induction
period of cholesterol.
Acta Crystallogr D Biol Crystallogr. 2002 Oct;58(Pt 10 Pt 1):1711-4.
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Influence of impurity ions and magnetic field on the properties of freshly precipitated calcium carbonate.
Holysz L, Chibowski E, Szczes A.
Department of Physical Chemistry, Faculty of Chemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
Static magnetic field (MF) effects on the properties of freshly
precipitated calcium carbonate have been investigated in the presence of
impurity ion Mg(2+), Fe(2+), or SO4(2-). One or both solutions, CaCl2
and Na2CO3, were exposure to MF (0.5T) for 20min at 20 degrees C. Then
calcium carbonate was precipitated and zeta potential, pH and light
absorbance (lambda=543.3 nm) were measured. The same parameters were
also determined for the reference systems in which the solutions were
not MF-treated. It was found that in all the systems tested MF effects
as determined by the above mentioned parameters had appeared. They
depended on the kind of the impurity ion present, as well as on which
solution, CaCl2, Na2CO3 or both, MF interacted. For example, if Mg(2+)
ion was present in CaCl2 solution, the largest shift in the zeta
potential toward higher positive values was observed if Na2CO3 was
MF-treated (e.g. from 2 to 12mV) and the same was true as for the
maximum in the light absorbance and the pH increase. Interestingly, if
(CaCl2 + Mg(2+)) was MF-treated pH of the slurry had decreased.
Moreover, a correlation between above mentioned MF effects and the
entropy of hydration of the ions has also been found. This points to the
changes in the hydrating water structure caused by magnetic field.
Water Res. 2003 Aug;37(14):3351-60.
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Electromagnetic noise blocks the gap-junctional intercellular communication suppression induced by 50 Hz magnetic field.
Zeng Q, Chiang H, Fu Y, Lu D, Xu Z.
Bioelectromagnetic Lab., Zhejiang University School of Medicine, Hangzhou 310031, China.
OBJECTIVE: To explore whether the superposition of an electromagnetic
noise can block gap-junctional intercellular communication(GJIC)
suppression induced by 50 Hz 0.4 mT extremely low frequency magnetic
field (ELF MF).
METHODS: Fibroblast cells of mice(NIH 3T3) were exposed to 0.4 mT ELF
MF or (and) electromagnetic noise with the same intensity of MF for 24
h, and the GJIC was determined by using fluorescence recovery after
photobleaching (FRAP) analysis, which was performed with a
laser-scanning confocal microscope (Leica, Germany).
RESULTS: ELF MF exposure significantly inhibited GJIC with
fluorescence recovery rate of 27.67% +/- 5.12% as compared with the
control group (45.57% +/- 9.72%) (P < 0.01), while that of ELF MF
plus noise group was (52.61% +/- 8.30%), which was significantly
different from ELF MF group (P < 0.01), but not from control (P >
0.05).
CONCLUSION: Electromagnetic noise could block the GJIC suppression induced by 50 Hz 0.4 mT MF.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2002 Aug; 20(4): 243-5.
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Effects of electromagnetic noise on the enhancement of
stress-activated protein kinase(SAPK) phosphorylation induced by 50 Hz
magnetic fields.
Sun W, Chiang H, Fu Y, Lu D, Xu Z.
Microwave Lab., Zhejiang University School of Medicine, Hangzhou 310031, China.
OBJECTIVE: To investigate the possible interference effect of
electromagnetic noise exposure on phosphorylation of stress-activated
protein kinase(SAPK) induced by 50 Hz magnetic field(MF).
METHODS: Chinese hamster lung(CHL) cells were exposed to sham
exposure(C), 0.4 mT 50 Hz sinusoidal MF, 0.4 mT electromagnetic noise
and the combined noise MF with 50 Hz MF for 3 min and 15 min
respectively. After exposure, the cells were lysed, and the proteins
were extracted. The SAPK and phosphorylated SAPK (activated form of
SAPK) were measured indirectly by Western blot with corresponding
antibodies. The percentage of phosphorylated SAPK was calculated and
analyzed.
RESULTS: Exposure of cells to 50 Hz MF for 3 min and 15 min enhanced
the SAPK phosphorylation. The percentage of phosphorylated SAPK were
49.3% and 57.0% respectively, and were significantly different from
those of control(P < 0.05, n = 4). However, single noise MF exposure
with the same intensity did not enhance the SAPK phosphorylation, the
percentage of phosphorylated SAPK were 37.7% and 31.8% (P > 0.05).
When cells were exposed to the combined noise MF with 50 Hz MF for 3
min, the SAPK phosphorylation was significantly inhibited (24.4%, P <
0.05); for 15 min, the SAPK phosphorylation was also decreased (39.0%),
but there was no significant difference from control and 50 Hz MF
exposure(P > 0.05).
CONCLUSION: Noise MF with certain intensity could inhibit the biological effect induced by 50 Hz MF.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2002 Aug; 20(4): 246-8.
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The efficiency and direction of thymus changes after whole-body
exposure of mice to the weak electromagnetic field are determined by the
initial status of the thymus.
Semin IuA, Zhavoronkov LP, Voron'ko IaV, Shvartsburg LK, Rozhkova OM.
Medical Radiological Research Center, Russian Academy of Medical Science, Obninsk, 249036 Russia. mrrc@obninsk.ru
The work presents results of the experimental study on thymus changes
developing after whole-body exposure of mice to ultralow power
pulse-modulated electromagnetic field (carrying frequency 2.39 GHz,
modulating pulses with frequency 4 Hz, duration of impulses 0.025 sec,
average power density 60 mW/cm2, absorbed dose 0.086 J/g or 0.172 J/g).
It was shown that a percent of the microwave induced increase or
decrease of thymus mass and the number of cells in the organ (y) are
determined by the initial mass or number of cells in thymus accordingly
to equation of linear regression: (yx = 215-2.25x, where x is the thymus
mass of control animals (in a range 31-63 mg) and (yx = 178.6-41x,
where x is the initial number of cells in thymus (in a range 0.6 x
10(8)-2.6 x 10(8)) reduced by a factor of 10(8).
Radiats Biol Radioecol. 2003 Sep-Oct;43(5):524-7.
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Kinetic parameters of androgen receptor complexes and the activities
of the glycolysis and oxidative pentose phosphate pathway key enzymes
in rat testis cytosol after whole body 60-min exposure to high frequency
electromagnetic field (39.5 Ghz).
Kopoplia EF, Popo v EG, Rybakov VN, Iakubovskii SM.
Institute of Radiobiology, Belarus National Academs of Sciences, Minsk, 220141 Belarus.
The effect of electromagnetic field of millimeter range on
biochemical indices of testicles of totally exposed rats at various
periods of observation (day 1, 10, 30, 90) was studied. The following
functional shifts were revealed: the 6-phosphogluconate dehydrogenase
activities enforced approximately up to 130% on 30th day in comparison
with the controls, but in three months (90th day) the activity returned
to normal values: glucose-6-phosphate dehydrogenase an puruvate kinase
did not show obvious changes of activities. On the contrary, there were
surprising differences in behavior of androgen-receptor system: the
number of androgen-receptor sites in cytosol was increased significantly
on 1st day after exposure (114%); on 10th day concentration of RA was
quite oppositely 1.68-fold reduced in relation to the control; through
1-month after exposure the rising of [RA] (123%) was registered;
however, to 3-month term the significant fall (1.42 times) of the RA
contents in testicular cytosol persisted.
Radiats Biol Radioecol. 2003 Sep-Oct;43(5):535-7.
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50 Hz magnetic fields activate mussel immunocyte p38 MAP kinase and induce HSP70 and 90.
Malagoli D, Lusvardi M, Gobba F, Ottaviani E.
Department of Animal Biology, University of Modena and Reggio Emilia, via Campi 213/D, 41100 Modena, Italy.
Fifty hertz magnetic fields (MFs) induced the expression of heat
shock proteins (HSPs) 70 and 90 in immunocytes of the mussel Mytilus
galloprovincialis. Animals exposed at 300 microT for three different
times (30; 2x30; 3x30 min), did not show differences in the HSP
densitometric values in comparison with non-exposed mussels. At 400
microT, exposed animals showed a time-dependent increase in HSP
expression as revealed by Western blot. After exposure to 600 microT,
the HSP densitometric values were significantly higher than controls but
not related to exposure duration. The induction of HSPs is concomitant
with the activation of p38 MAP kinase signalling pathway. The present
findings suggest the possibility to modulate the expression of HSPs by
an appropriate time-intensity magnetic field exposure.
Comp Biochem Physiol C Toxicol Pharmacol. 2004 Jan;137(1):75-9.
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