NeuroTherm

Jul 12, 2020

Akira Nishioka,1 Maiko Kimura,1 Eriko Sakamoto,1 Hiroshi Nagasaka,2 Toshiharu Azma1,2 1Department of Anesthesiology & Pain Medicine, Kohondai Hospital, National Center for Global Health and Medicine, Ichikawa, Chiba 272-8516, Japan; 2Department of Anesthesiology, Saitama Medical University Hospital, Iruma, Saitama 350-0495, Japan Correspondence: Toshiharu Azma Department of Anesthesiology & Pain Medicine, Kohondai Hospital, National Center for Global Health and Medicine, Ichikawa, Chiba 272-8516, Japan Email azma@hospk.ncgm.go.jp Background: The application of pulsed radiofrequency (PRF) current to peripheral nerves with conditions related to neuropathic pain is considered to be clinically safe, while it has been reported that the destruction of mitochondria after PRF application was observed by electron microscopy. If it occurs reproducibly, PRF applied to peripheral nerves should provoke neurolysis because the impairment of mitochondria is known as the primary cause of apoptosis. Methods: Human monocytic cells THP-1 loaded with 100 nM tetramethylrhodamine methyl ester (TMRM), a fluorescent dye that proves the mitochondrial membrane potential (MMP), were exposed to the electric field of continuous radiofrequency (CRF) or PRF current. The TMRM-related fluorescence from THP-1 cells was measured by flow cytometry. Results: The exposure of THP-1 cells to a PRF electric field generated by NeuroTherm NT500 for 15 min with maximum power did not decrease MMP in these cells, nor did it cause the induction of apoptosis. By contrast, the application of CRF current at 70 °C for 3 min significantly decreased MMP and induced apoptosis within 10 min after CRF application. Conclusion: We conclude from these findings that PRF application does not provoke mitochondrial injury in various types of mammalian cells because the size and the subcellular structure of the plasma membrane or mitochondria are similar among those. However, the present results cannot address the effect of PRF current on organic structure around the nervous system. Further study is required to solve the question of whether PRF current causes neurolysis or not. Keywords: pulsed radiofrequency current, human monocytic cells, THP-1, mitochondrial membrane potential, apoptosis This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License . By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms .