EFFECTS OF AMBIENT ELF MAGNETIC FIELDS: VARIATIONS IN ELECTROLYTE LEVELS IN THE BRAIN AND BLOOD PLASMA

Purpose: To determine whether concentrations in the brain and plasma tissu- es are influenced by ELF magnetic fields. Methods: Male, 250-300 g guinea pigs were kept under the laboratory condi- tions of 23 °C, a day and night cycle of 12 hours and an ambient geomagnetic field of 30 μT (microTeslas) in plastic cages. The subjects were divided into two groups: a control group (n=11) and an experimental group (n=24), which was exposed to a 50 Hz, 2 mT field for 4 hours/day for 5 days. The control subjects were handled in an identical manner without being exposed to any magnetic field. After the completion of the experiment, blood samples from the control and exposed animals were collected by cardiac puncture without hemolysis. The animals were sacrificed by ether inhalation in a closed box; then their brains were dissected out immediately. Cu++, Zn++, Ca++ and Mg++ concentrations in both the plasma and brain tissue of guinea pigs were determined by flame atomic absorption. Na+ and K+ concentrations in the plasma were measured by direct application to flame photometry. Results: Na+, Ca++ and Mg++ concentrations in the blood plasma increased while Zn++ and K+ concentrations decreased with the effect of the magnetic field. The increase in the Ca++ concentration was statistically significant. The Cu++ concentration was not affected by magnetic field exposure. The magnetic field, having a greater effect on Zn++ and Mg++ concentrations, increased Cu++, Zn++, Ca++ and Mg++ concentrations in the brain tissue. Conclusion: The ELF magnetic field altered the Ca++ concentration in the brain and plasma tissues. It is generally thought that the cell membrane is the first target of external fields, and calcium regulated activity is involved in ELF field coupling to living systems. Our results appear consistent with this hypothesis. Key Words: ELF Magnetic Fields, Guinea Pigs, Brain Electrolytes, Plasma Electrolytes CEVRESEL ELF MANYETIK ALANLARIN ETKILERI: BEYIN VE PLAZMA ELEKTROLIT SEVIYELERINDE DEĞIŞIMLER Amac: Bu calismada, ELF frekansli manyetik alanlarin beyin ve plazma elektrolit duzeylerini etkileyip etkilemedigini arastirmak amaclanmistir. Yontem: Erkek, 250-300 g agirlikta kobaylar, sicakligi 23 °C, geomanye- tik alani 30 μT (mikroTesla) olan laboratuarda plastik kafeslerde ve 12 saat gece-12 saat gunduz kosullarinda muhafaza edildi. Kontrol ve deney grubu olmak uzere iki gruba ayrildi; kontrol grubu kobaylari (n=11) ayni laboratuar sartlarinda manyetik alana maruz birakilmadan tutuldu. Deney grubu (n=24) ise gunde 4 saat olmak uzere 5 gun boyunca 50 Hz, 2 mT manyetik alana maruz birakildi. Maruziyet tamamlandiginda tum hayvanlarin kan ornekleri enjektor ile dogrudan kalbe girerek alindi, bunu takiben hayvanlar eter ile bayiltildi ve beyin dokulari cikarildi. Plazma be beyin Cu++, Zn++, Ca++ ve Mg++ konsantrasyonlari atomik absorbsiyon teknigi ile Na+ ve K+ ise dog- rudan plazmanin alev fotometre cihazina uygulanmasi yoluyla tesbit edildi. Bulgular: Plazma Na+, Ca++ ve Mg++ duzeylerinin manyetik alan etkisi ile artmis oldugu, Zn++ ve K+ seviyelerinin ise azalmis oldugu belirlendi. Ca++ seviyesindeki artis istatistiksel anlamda onemli bulundu. Cu++ duzeyi manyetik alandan etkilenmedi. Beyin dokusu Cu++, Zn++, Ca++ ve Mg++ konsantrasyonlari artmis bulundu, ancak Zn++ ve Mg++’un manyetik alan- dan daha fazla etkilenmis oldugu saptandi. Sonuc: ELF manyetik alanin beyin ve plazmada Ca++ miktarini etkiledigi belirlendi. Dis kaynakli alanlarin hedefinin hucre membrani oldugu ve ELF alanlarin canli sistemlerle etkilesebilmesi icin Ca++ tarafindan duzenlenen mekanizmalara ihtiyac duyuldugu yonunde bir genel inanis olusmustur. Bi- zim bulgularimiz da bu hipotezi destekler gorunmektedir. Anahtar Kelimeler: ELF Manyetik Alanlar, Kobay, Beyin Elektrolitleri, Plazma Elektrolitleri