The effects of combination of RF and pulsed magnetic field on carotid arteria ischemia and reperfusion induced brain injury: A preliminary report

Abstract

ABSTRACT Objective: A cerebrovascular accident can trigger inflammation in the cerebral cortex, hippocampus, and cerebellum tissues due to ischemia mediated by atherosclerotic plaque in the brain. Radiofrequency electromagnetic field (RF-EMF) and pulsed magnetic field (PMF) applications can increase nitric oxide formation from the vascular endothelial layer. The aim of this preliminary study is to reduce the damage in different tissues of the brain caused by ischemia. Material and Methods: Nine rats were grouped as sham (only neck dissection applied and put into RF-EMF and PMF unit for 0-30 minutes without operating the device), Prophylactic RF-EMF+IR, Prophylactic PMF+IR, Prophylactic RF-EMF+PMF+IR, Therapeutic RF-EMF+IR, Therapeutic PMF+IR, Therapeutic RF-EMF+PMF+IR, Prophylactic+Therapeutic RF-EMF+PMF+IR, and IR (carotid artery occlusion and reperfusion applied 30 min for both). In single or combined applications of prophylactic/therapeutic RF-EMF and PMF groups, rats were put into the experimental unit for 30 minutes of magnetic field exposure before and after ischemia. After sacrification, brain tissues were collected for hematoxylin-eosin staining and immunohistochemical analyses as brainderived neurotrophic factor (BDNF), tumor necrosis factor-alpha (TNF-α), the mammalian target of rapamycin (mTOR) and inducible nitric oxide synthase (iNOS) expressions. Results: In the IR group, marked hyperemia, edema, hemorrhage, and neuronal degenerations were diagnosed histopathologically. Also, increased TNF-α, mTOR, iNOS, and decreased BDNF staining were observed immunohistochemically. Prophylactic and/or Therapeutic RF-EMF and/or PMF applications reversed all these parameters. The most amelioration was observed in the Prophylactic+Therapeutic RF-EMF+PMF+IR group. Conclusion: In conclusion, the regression of the inflammatory scene due to ischemia in all three tissues with RF-EMF and PMF is important in terms of the occurrence of neurological deficits, the continuity of learning and memory mechanisms, and the preservation of balance functions.