مطالعه استريولوژيك تغييرات حجمي قلب ناشي از قرارگيري در ميدان الكترومغناطيس درموش صحرايي نر

Stereologicalstudy of heart volume in male rats after exposure to electromagnetic fields

Background: Usage of equipments producing electromagnetic radiations are increasing in daily life of most societies. The probable effects of these waves, even with low intensity, on different organs are focused by many researchers. The present research was designed to study the effects of electromagnetic field (EMF) on heart muscular walls and cavities, for the first time. Methods. A total of 24 wistar male rats were divided into one control group, one sham group and 2 experimental groups (4 animals in each group). The experimental groups were exposed continually to 2.1 and 4.3 mT of electromagnetic fields for 6 and 15 days, respectively. The sham group was maintained in similar conditions in the off fields and for the control group no operation was done. At the end of the experiment, animals were sacrificed and their hearts were extracted. Serial sections with l\im thickness were prepared and stained by hematoxylin & eosin. Total volume of heart, volume of right and left ventricular wall and cavity and interventricular septum were measured by Cavalierʹs method and stereological coefficient error were calculated for all groups. Results: There were no significant differences between 15 days exposure groups compared to control and sham groups. In the 6 day exposure with intensity of 2.1 mT group, the volume of left and right ventricular walls were decreased significantly. There was significant increase in interventricular septum of the 6 day exposure group with intensity of 4.3 mT. Conclusion: Short time exposure of low intensity EMF probably will affect growth or blood supply of heart muscles by producing free radicals but animals that exposed to same condition for longer time will adapt to EMF and show the normal state. This adaptive phenomenon may be due to coordination of CNS and circulatory system.