Effects of electroacupuncture on orphanin FQ immunoreactivity and preproorphanin FQ mRNA in nucleus of raphe magnus in the neuropathic pain rats.
Orphanin FQ (OFQ) is an endogenous ligand for opioid receptor-like-1 (ORL1) receptor. Previous studies have shown that both OFQ immunoreactivity and preproorphanin FQ (ppOFQ) mRNA expression could be observed in the brain regions involved in pain modulation, e.g., nucleus of raphe magnus (NRM), dorsal raphe nucleus (DRN), and ventrolateral periaqueductal gray (vlPAG). It was reported that electroacupuncture (EA) has analgesic effect on neuropathic pain, and the analgesic effect was mediated by the endogenous opioid peptides. In the present study, we investigated the effects of EA on the changes of OFQ in the neuropathic pain rats. In the sciatic nerve chronic constriction injury (CCI) model, we investigated the changes of ppOFQ mRNA and OFQ immunoreactivity in NRM after EA by in situ hybridization (ISH) and immunohistochemistry methods, respectively. Then, the ppOFQ mRNA-positive and OFQ immunoreactive cells were counted under a computerized image analysis system. The results showed that expression of ppOFQ mRNA decreased and OFQ immunoreactivity increased after EA treatment in the neuropathic pain rats. These results indicated that EA modulated OFQ synthesis and OFQ peptide level in NRM of the neuropathic pain rats.
Ma
Fei
F
Department of Integrative Medicine, Institute of Acupuncture Research, Shanghai Medical College, Fudan University, P.O. Box 291, 138 Yi Xue Yuan Road, Shanghai 200032, China.
Xie
Hong
H
Dong
Zhi-Qiang
ZQ
Wang
Yan-Qing
YQ
Wu
Gen-Cheng
GC
D000704:Analysis of Variance; D000818:Animals; D015671:Electroacupuncture; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D018847:Opioid Peptides / Q000235:genetics / Q000378:metabolism*; D010146:Pain / Q000209:etiology / Q000378:metabolism*; D059408:Pain Management; D012333:RNA, Messenger / Q000378:metabolism; D011903:Raphe Nuclei / Q000378:metabolism / Q000528:radiation effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020426:Sciatic Neuropathy / Q000150:complications / Q000628:therapy; D000097629:Nociceptin
D018847:Opioid Peptides; D012333:RNA, Messenger; D000097629:Nociceptin