Pulsed radiofrequency (PRF) treatments for chronic pain consist in the delivery of a train of sinusoidal electric bursts to the targeted nerve. Despite numerous clinical evidence of its efficiency, the mechanism of action of PRF remains unclear. Since most of the reported biological effects of PRF can be initiated by a calcium influx into the neurons, we hypothesized that PRF may induce a mild electroporation effect causing a calcium uptake. To test this hypothesis, HEK-293 cells were exposed to PRF bursts and cytosolic calcium and Yo-Pro-1 uptake were monitored. After a single burst, calcium peaks were observed for electric fields above 480 V/cm while the uptake of Yo-pro-1 was insignificant. After a train of 120 bursts, the electric fields required to induce a calcium and Yo-pro-1 uptake decreased to 330 V/cm and 880 V/cm respectively. Calcium peaks were not detected when cells were treated in calcium free media. The temperature increase during the treatments was lower than 5 °C in all cases. Finally, the cell response for different burst frequencies and extracellular media conductivities correlated with the induced transmembrane voltage calculated with a numerical model. Our results support the hypothesis of an electroporation mediated calcium influx.

用于慢性疼痛的脉冲射频（PRF）治疗包括向目标神经传递一系列正弦电脉冲。尽管有许多临床证据表明其有效，但PRF的作用机制仍不清楚。由于大多数报道的PRF的生物学效应可以通过钙流入神经元来引发，因此我们假设PRF可能诱导轻度的电穿孔作用，导致钙吸收。为了验证该假设，将HEK-293细胞暴露于PRF脉冲下，并监测细胞质钙和Yo-Pro-1的摄取。单次爆发后，在480 V / cm以上的电场中观察到钙峰，而对Yo-pro-1的摄取微不足道。经过一连串的120次爆发后，诱导钙和Yo-pro-1摄取所需的电场分别降至330 V / cm和880 V / cm。在无钙培养基中处理细胞时未检测到钙峰。在所有情况下，治疗期间的温度升高均低于5°C。最后，对于不同的猝发频率和细胞外介质电导率的细胞响应与通过数值模型计算的诱导跨膜电压相关。我们的结果支持了电穿孔介导的钙内流的假设。