Changes of expression of glial cell line-derived neurotrophic factor and its receptor in dorsal root ganglions and spinal dorsal horn during electroacupuncture treatment in neuropathic pain rats.
Injury to the nervous system occasionally leads to intense and persistent neuropathic pain, which is resistant to conventional analgesic methods. It was reported that electroacupuncture (EA) had potent analgesic effect on neuropathic pain by activating various endogenous transmitters such as the opioid peptides. Glial cell line-derived neurotrophic factor (GDNF) has been hypothesized to play an important role in modulation of nociceptive signals especially during neuropathic pain state. Using immunohistochemistry, Western blot, and RT-PCR analysis techniques, the present study observed the effects of EA on the expression of GDNF and GDNF family receptor alpha-1 (GFRalpha-1, the high-affinity receptor of GDNF) in neuropathic pain rats. The results showed that both protein and mRNA levels of GDNF and GFRalpha-1 in the dorsal root ganglions (DRG), as well as GDNF protein in the spinal dorsal horn, were significantly increased after chronic constriction injury (CCI) of the rats' sciatic nerve and could be further enhanced by EA treatment. The present data demonstrated that EA could activate endogenous GDNF and GFRalpha-1 system of neuropathic pain rats and this might underlie the effectiveness of EA in the treatment of neuropathic pain.
Dong
Zhi-Qiang
ZQ
Department of Integrative Medicine and Neurobiology, Institute of Acupuncture Research, Shanghai Medical College, Fudan University, P.O. Box 291, 138 Yi Xue Yuan Road, Shanghai 200032, China.
Ma
Fei
F
Xie
Hong
H
Wang
Yan-Qing
YQ
Wu
Gen-Cheng
GC
D000818:Animals; D015153:Blotting, Western; D004195:Disease Models, Animal; D015671:Electroacupuncture; D005727:Ganglia, Spinal / Q000378:metabolism*; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D007150:Immunohistochemistry; D008297:Male; D009414:Nerve Growth Factors / Q000096:biosynthesis*; D009437:Neuralgia / Q000628:therapy*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D051096:Proto-Oncogene Proteins c-ret; D051381:Rats; D017207:Rats, Sprague-Dawley; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000378:metabolism*
C495041:Gdnf protein, rat; C494989:Gfra1 protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009414:Nerve Growth Factors; D011518:Proto-Oncogene Proteins; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases