RESUMEN
INTRODUCTION: In daily life biological systems are usually exposed to magnetic field forces at different intensities and frequencies, either directly or indirectly. Despite negative results, the therapeutic use of the low dose magnetic field has been found in recent studies. The effect of magnetic field forces on cochlear cells is not clear in the literature. OBJECTIVE: In our study, we first applied in vivo pulsed magnetic fields to laboratory rats to investigate the effects on cochlea with distortion product otoacoustic emission test followed by histopathological examinations. METHODS: Twelve rats were included in this study, separated into two groups as study group and control group. The rats in the study group were exposed to 40Hz pulsed magnetic field for 1h/day for 30 days; the hearing of the rats was controlled by otoacoustic emission test. Also, their cochleas were removed and histochemical examination was performed by Caspase-3, Caspase-9, and TUNEL methods. RESULTS: A statistically significant difference was determined (p<0.05) when the hearing thresholds of the groups obtained by using 5714Hz and 8000Hz stimuli were compared by Kruskal-Wallis test. A significant reaction was observed in the study group, especially in the outer ciliated cells during immunohistochemical examinations by using Caspase-3 and Caspase-9 methods. A significantly positive difference was determined in the study group, especially at the outer ciliated cells and the support cells of the corti organ, when compared to the control group (p<0.05) by the TUNEL method. CONCLUSION: According to the results of our study, the very low dose magnetic field, which is considered to be used for therapeutic purposes recently, can cause both auditory function defects and histopathologic damage in cochlear cells.
Asunto(s)
Cóclea/patología , Campos Electromagnéticos/efectos adversos , Células Ciliadas Auditivas Externas/patología , Animales , Inmunohistoquímica , Masculino , Emisiones Otoacústicas Espontáneas , Ratas , Ratas Wistar , Estadísticas no ParamétricasRESUMEN
The aim of in this study was to determine the effect of chronic alternating current (AC) magnetic field on the contraction and relaxation parameters of isolated thoracic aorta rings in healthy and diabetic rats. Sixty rats (Wistar albino spp) weighing between 250-300 g were used. The rats were divided into four groups: 1-Control (C), 2- control + magnetic field (C+MA), 3- experimental diabetic (DIA), 4- experimental diabetic and magnetic field (DIA+MA). Magnetic fields of 5 mT intensity and 50 Hz frequency oriented in the north-south direction was applied to the C+MA and DIA+MA groups for 2 hours each day for one month, after which rats were killed by decapitation and the thoracic aorta dissected. This showed attenuated contraction responses to phenylephrine (PE) and elevated relaxation responses to acetylcholine (ACh) of the thoracic aorta rings of rats in the C+MA and DIA+MA groups compared to group C but no changes in the relaxation responses to sodium nitroprruside (SNP) of thoracic aorta rings relative to group C and DIA. The weights of rats in DIA+MA or C+MA groups compared to the DIA and C groups decreased.