Ali AŞKIN, Ülkü ÇÖMELEKOĞLU, Yusuf ÇAMLICA

Radyofrekans Işımanın (900 MHz) Kurbağa Siyatik Siniri Üzerine Elektrofizyolojik Etkileri

Türkçe Özet:Amaç: Bu çalışmada, 900 MHz radyofrekans ışımanın kurbağa (Rana ridibunda) siyatik sinir bileşik aksiyon potansiyeli üzerine etkisinin incelenmesi amaçlanmıştır. Yöntem: On dört yetişkin kurbağa, her biri 7 hayvandan oluşan iki bağımsız gruba ayrılmıştır. 1. grup kontrol grubu, 2. grup 10 gün süreyle günde 4 saat 900 MHz radyofrekans ışıma uygulanan deney grubundan oluşmuştur. Kontrol grubu aynı gün ve sürede radyofrekans ışıma uygulanmadan aynı çevresel koşullarda tutulmuştur. Uygulama süresi sonunda izole siyatik sinirler, 0.5 ms süreli supramaksimal pulslarla uyarılmıştır. Hücre dışı kayıt yöntemi kullanılarak kaydedilen aksiyon potansiyellerinden tepeden tepeye genlik, depolarizasyon süresi, repolarizasyon süresi ve alan ölçülmüştür. Bulgular: Radyofrekans ışıma uygulanan gruptaki aksiyon potansiyeli değişkenlerinden genlik ve alan kontrol grubuna göre anlamlı olarak azalmıştır. Depolarizasyon ve repolarizasyon sürelerinde ise anlamlı bir fark bulunmamıştır. Sonuç: Bu bulgular mobil telefonlardan yayılan 900 MHz radyofrekans dalgalarının siyatik sinir aksiyon potansiyellerinin genliği ve alanını azalttığını, ancak depolarizasyon ve repolarizasyon sürelerini değiştirmediğini göstermiştir.

Anahtar Kelimeler:

radyofrekans radyasyon, cep telefonu, aksiyon potansiyeli, siyatik sinir.

Radyofrekans Işımanın (900 MHz) Kurbağa Siyatik Siniri Üzerine Elektrofizyolojik Etkileri

AbstractElectrophysiological Effects of Radiofrequency Radiation (900 MHz) on Frog Sciatic Nerve Objective: In this study, it was aimed to investigate the compound action potential parameters in isolated sciatic nerve of frog (Rana ridibunda) after exposure to 900 MHz radiofrequency radiation. Methods: 14 adult frogs were divided into two independet groups. For each group 7 animals were used. Group 1 included control. Group 2 (radiofrequency exposed group) was exposed to 900 MHz radiofrequency radiation for 4 h/day for 10 days. Control group was kept under the same environmental conditions as the study group except with no radiofrequency radiation exposure. At the end of the study isolated sciatic nerves were stimulated with 0.5 ms supramaximal pulses and action potential parameters as pick to pick amplitude, duration of depolarization and repolarization as well as area were measured with extracellular recording techniques. Results: In the radiofrequence group, the values of amplitude and area were significantly lower than the values of the control group. However, there were no significant changes in values of the duration of depolarization and repolarization of action potential in the sciatic nerves. Conclusion: These findings indicate that 900 MHz radiofrequency emitting mobile phones reduced the amplitude and area, but they have no effect on the duration of depolarization and repolarization of action potential in isolated frog nerve.

Keywords:

radiofrequency radiation, cellular phone, action potentials, sciatic nerve,

PDF

___

Adey WR, Byus CV, Cain CD, Higgins RJ, Jones RA, Kean CJ, Kuster N, McMurray A, Stagg RB, Zimmermann G, Phillips JI, Haggrenn W. Spontaneous and nitosourea— induced primary tumors of the central nervous system in Fischer 344 rats chronically exposed to 836 MHZ modulated microwaves. Radiat Res 1999;152:293—302.
Adey WR, Byus CV, Cain CD, Higgins RJ, Jones RA, Kean CJ, Kuster N, McMurray A, Stag RB, Zimmermann G. Spontaneous and nitrosourea-induced primary tumors of the central nervous system in Fischer 344 rats exposed to frequency—modulated microwave Şelds. Cancer Res ;60:l857—63. Zook BC, Simmens SJ. The effects of 860 MHZ radiofrequency radiations on the induction or promotion of brain tumors and other neoplasms in rats. Radiat Res ;155:572-83. Lai H, Carino MA, Horita A, Guy AW. Low—level microwave irradiation affects central cholinergic activity in the rat. J Neurochem 1987;48: 40—5.
Modak AT, Stavinoha WB, Dean UP. Effect of short electromagnetic pulsus on brain acetylcholine content and spontaneous motoric activity in mice. Bioelectromagnetics ;2289-92.
Mausset Al, Seze RD, Montpeyroux F, Privat A. Effect of radiofrequency exposure on the GABAergic system in the rat cerebellum clues from semi—quantitative immunohistochemistry. Brain Res 2001;912:33-46.
Lai H, Carino MA, Horita A, Guy AW. Low-level microwave irridiation and central cholinergic system. Pharmacol Biochem Behav 1989;33:131—8.
Mann K, Röschke ]. Effect of pulsed high—frequency electromagnetic fields on human sleep. Neuropsychobiology 1996;33:41-7.
Salford LG, Brun A, Sturesson K, Eberhardt JL, Persson BRR. Permeability of the blood—brain barrier induced by Selmaoui B, Lambrozo J, Touitou Y. Endocrine functions in young men exposed for one night to 50 Hz magnetic Koyu A, Cesur G, Ozguner F, Akdogan M, Mollaoglu H, Ozen S. Effects of 900 MHZ electromagnetic field on Walleczek J. Electromacnetic Şeld effects on the cell of the immune system. FASEB J 1992;623177—85.
Seaman RL, Wachtel H. Slow and rapid responses to CW and pulsed microwave radiation by individual Aplysia pacemakers. J Microwave Power 1978;13:77-86.
Chou CK, Guy AW. Effects of electromagnetic Şelds on isolated nerve and muscle preparation. IEEE Trans Microw Andrew BL. Experimental Churchill Livingstone, London, 1972.
Katz B. Nerve, muscle and synapse. McGraw Hill Book Company, New York, 1966.
Daube JR. Alteration of wave forms and artefacts. In Daube JR, Ed., Clinical neurophysiology. Philadelphia, FA McRee DI, Wachtel H. The effects of microwave radiation on the vitality of isolated frog sciatic nerves. Radiat Res ;82:536—46.