O efeito da radiação emitida por telefones móveis sobre os processos de sinalização intracelular das células hipofisárias

Abstract

In the last few years, the mobile telecommunication system has improved significantly, making one sixth of the world`s population to use mobile phones, which means, in numbers, that more than a billion of people are using such devices nowadays (National Radiological Protection Board, 2004; Maier, 2006). In 2011, the number of habilitations in Brazil has reached more than 202,9 millions, corresponding a density of 104,68 phones for each hundred of habitants (Anatel, 2011). Studies about the effects of radiation transmitted by mobile phones to the organism are still very few, the results are contradictories and most of them are made in cell cultures or ex vivo cells to further exposure to radiation. Thus, the objectives of this study were to establish an animal model in order to investigate the effect of the electromagnetic radiation emitted by mobile phones into the physiology of rats and to evaluate the role of this type of radiation in the expression and activity of ERK 1 and ERK 2 and the expression of isoform alpha from PKC in pituitary gland. 60 days-old Wistar rats were used. The source of radiation was a mobile phone with a frequency of 1800 MHz. Four experimental groups were established: 1- animals exposed for 1 hour; 2- animals exposed for 3h; 3- animals exposed for 3 days; 4- animals exposed for 10 days. In the experiments of 3 and 10 days, the exposure was 25 seconds in every 2 minutes. Each experimental group was followed by a control group. The capacity of the radiation to cross the animal’s cranial bones, and to heat the water under the cranial region, was measured. The effect of the radiation emitted by the mobile phone on ERK 1 and ERK 2 expression and activity, and expression of isoform alpha of PKC in pituitary gland were evaluated. It was shown that the radiation is capable of crossing the cranial region. It was not observed any effect of the radiation into the water temperature. After 1 hour of exposure it were observed a significant reduction in ERK 1 and ERK 2 activity of the animals exposed to radiation. This inhibitory effect was kept in the experiments of 3 hours and 3 days as well. At the tenth day, the activity of ERK 1 and ERK 2 of control and exposed group was similar. The expression of PKC-alpha has only changed in the animals exposed to 3 days of radiation. According to these results, we conclude that radiation emitted by mobile phones, in this experimental model, affects important signaling pathways in the pituitary cells, but further studies with more details are needed to determine the consequences of the modifications observed.