Pulsed radiofrequency reduced complete Freund's adjuvant-induced mechanical hyperalgesia via the spinal c-Jun N-terminal kinase pathway.
Pulsed radiofrequency (PRF) treatment involves the pulsed application of a radiofrequency electric field to a nerve. The technology offers pain relief for patients suffering from chronic pain who do not respond well to conventional treatments. We tested whether PRF treatment attenuated complete Freund's adjuvant (CFA) induced inflammatory pain. The profile of spinal c-Jun N-terminal kinases (JNKs) phosphorylation was evaluated to elucidate the potential mechanism. Injection of CFA into the unilateral hind paw of rats induced mechanical hyperalgesia in both the ipsilateral and contralateral hind paws. We administered 500-kHz PRF treatment in 20-ms pulses, at a rate of 2 Hz (2 pulses per second) either to the sciatic nerve in the mid-thigh, or to the L4 anterior primary ramus just distal to the intervertebral foramen in both the CFA group and no-PRF group rats. Tissue samples were examined at 1, 3, 7, and 14 days following PRF treatments. Behavioral studies showed that PRF applied close to the dorsal root ganglion (DRG) significantly attenuated CFA-induced mechanical hyperalgesia compared to no-PRF group (P < .05). And western blotting revealed significant attenuation of the activation of JNK in the spinal dorsal horn compared to no-PRF group animals (P < .05). Application of PRF close to DRG provides an effective treatment for CFA-induced persistent mechanical hyperalgesia by attenuating JNK activation in the spinal dorsal horn.
Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No.123, Dapi Rd., Niaosong Dist., Kaohsiung, 833, Taiwan.
Kuan-Hung
KH
Chen
Chien-Hui
CH
Yang
Sin-Ei
SE
Juang
Hui-Wen
HW
Huang
Jen-Kun
JK
Cheng
Shyr-Ming
SM
Sheen-Chen
Jiin-Tsuey
JT
Cheng
Chung-Ren
CR
Lin
D000818:Animals; D015153:Blotting, Western; D004789:Enzyme Activation; D005620:Freund's Adjuvant; D005727:Ganglia, Spinal / Q000201:enzymology / Q000473:pathology; D006930:Hyperalgesia / Q000139:chemically induced* / Q000150:complications / Q000628:therapy*; D007249:Inflammation / Q000150:complications / Q000473:pathology; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D008297:Male; D010146:Pain / Q000150:complications / Q000473:pathology; D061208:Pulsed Radiofrequency Treatment; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000201:enzymology* / Q000473:pathology*; D013997:Time Factors
D005620:Freund's Adjuvant; D048031:JNK Mitogen-Activated Protein Kinases