<p>Continuous But Not Pulsed Radiofrequency Current Generated by NeuroTherm NT500 Impairs Mitochondrial Membrane Potential in Human Monocytic Cells THP-1</p>

Abstract

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.

Effects of continuous and pulsed radiofrequency applied for 120 and 240 seconds to rats' sciatic nerve

“…[21] In human peripheral nerves, it has been shown that C-RF can cause mitochondrial changes and lead to apoptosis. [25] We did not detect significant changes in light microscopy or electron microscopy in the C120 group. Thus, our study differs from Vatansever's study, and we only observed similar results to Tun's study in the C240 group, not in the C120 group.…”

“…It has been shown that P-RF does not cause morphological changes in mitochondria or induce apoptosis in human peripheral nerves. [25] Several studies demonstrate that P-RF can have a positive histological effect on damaged nerves. Zhu et al [30] demonstrated that P-RF can promote nerve repair by increasing the level of GDNF and decreasing the level of GFAP.…”