Acta Medica Medianae (Mar 2010)
BIOCHEMICAL AND HISTOPATHOLOGICAL EFFECTS OF MOBILE PHONE EXPOSURE ON RAT HEPATOCYTES AND BRAIN
Abstract
Microwave radiation MWR is widespread in human environment. The most frequent sources of MWR are mobile phones and cell towers. The effects of MWR are still unknown and there are insufficient data about long-term MWR effects on hepatocytes and brain structures.The aim of this paper was to investigate the biological effects of mobile phone microwave radiation on the brain and liver of experimental animals and to determine the increase in oxidative stress as a possible pathogenetic mechanism for harmful effects of long-term exposure.Wistar rats, 3 months old, were divided into two groups: I-rats constantly exposed to MWR (3 female and 2 male) and II-control animals without near source of electromagnetic field (EMF) (3 female and 2 male). The microwave radiation was produced by a mobile test phone (model NOKIA 3110; Nokia Mobile Phones Ltd.) connected to a Communication Test Set (model 4202S; Wavetek, Germany). A 900 MHz electromagnetic near-field signal for GSM (Global System for Mobile communication at 900 MHz, continuous wave, analog phone) system was used. The whole-body specific energy absorption (SAR) rate was estimated as 0.025-0.05 W/kg (E=9.8-18.3 V/m, B=4.8-8.6 µT). Rats were sacrificed after 3 months of MWR exposure. The liver and brain were fixed in 10% formaldehyde and paraffin sections were stained by HE. The biochemical analyses comprised the determination of serum activity of AST (Aspartate aminotransferase), ALT (Alanine transaminase), GGT (Gamma-glutamyl transpeptidase) and LDH (Lactate dehydrogenase), as well as determination of serum concentration of sodium, potassium and chloride. Lipid peroxidation was determined by measuring the quantity of malondialdehyde (MDA).Slightly increased number of micronuclei and discrete perivenular fatty changes were only histopathological findings in the liver of exposed rats. The discrete reduction of gray matter and reduced size and number of dendritic spines of Purkinje cells in cerebellum were notified as well. The serum activity of ALT was significantly increased (p<0.05), while activities of AST, GGT and LDH did not changed in the exposed rats. Potassium serum concentration was significantly higher in the exposed rats, while the concentration of sodium and chloride did not differ. The MDA concentration was significantly higher in the brain and liver tissues of MWR-exposed rats.The results in this study show significant increase in lipid peroxidation as a direct indicator of the hepatocytes and brain cells’ injury under a long-term (90 days) mobile phone microwave exposure. The hyperkalemia could be the possible systemic marker of impaired cells membrane fluidy and increased permeability, alongside with increased ALT activity as marker of hepatocelular damage. Disorders of hypothalamo- hypophyseal axis lead to disturbances in affective behaviour, but also to disturbances of neurovegetative functions, which leads to behavioral changes and increased appetite and weight gain in exposed animals.
