title: Antinociceptive roles of galanin receptor 1 in nucleus accumbens of rats in a model of neuropathic pain.
abstract: It has been reported that galanin and its receptors might be involved in the modulation and transmission of nociception in the central nervous system. Our previous research has also demonstrated that galanin induces antinociception in the nucleus accumbens (NAc) of intact rats. However, the interaction between galanin and its receptors in the NAc and the underlying mechanism of suppressing pain transmission remain unclear. The present study seeks to determine the antinociception induced by galanin receptor (GalR)-1 stimulation in the NAc of rats with neuropathic pain. The left sciatic nerve of rats was ligated to mimic a neuropathic pain model. Western blots showed that the expression of GalR1 was significantly upregulated in the NAc of rats with neuropathic pain. Intra-NAc injection of GalR1 agonist M617 induced a dose-dependent increase in hindpaw withdrawal latency (HWL) to noxious thermal and mechanical stimulations in rats with neuropathic pain. Also, the effect of M617 was attenuated by M35, a GalR1/2 antagonist; at the same time, M35 reduced the galanin-induced antinociception, suggesting that GalR1 mediates antinociception induced by galanin in the NAc of rats with neuropathic pain. Furthermore, we found that M617-induced antinociception in rats with neuropathic pain was stronger than the antinociception in intact rats. We also found that injections of M617 and galanin each induced significant increases in HWL, but the galanin-induced antinociception was stronger than that of M617. All these results suggest that GalR1 plays an important role in antinociception and that other GalRs also are involved in pain modulation induced by galanin in the NAc of rats with neuropathic pain.
authors.affiliation: Department of Physiology, School of Basic Medicine, Kunming Medical University, Chenggong, Kunming, Yunnan, People's Republic of China.|Department of Orthopedics, Second Affiliated Hospital, Kunming Medical University, Xishan, Kunming, Yunnan, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Duan
authors.affiliation: Department of Pathophysiology, School of Basic Medicine, Kunming Medical University, Chenggong, Kunming, Yunnan, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Physiology, School of Basic Medicine, Kunming Medical University, Chenggong, Kunming, Yunnan, People's Republic of China.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Zhang
authors.affiliation: Department of Pathophysiology, School of Basic Medicine, Kunming Medical University, Chenggong, Kunming, Yunnan, People's Republic of China.
authors.forename: Huan-Huan
authors.initials: HH
authors.lastname: Xu
authors.affiliation: Department of Orthopedics, Second Affiliated Hospital, Kunming Medical University, Xishan, Kunming, Yunnan, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Shu
authors.affiliation: Department of Physiology, School of Basic Medicine, Kunming Medical University, Chenggong, Kunming, Yunnan, People's Republic of China.
authors.forename: Shi-Lian
authors.initials: SL
authors.lastname: Xu
mesh_terms: D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use*; D000704:Analysis of Variance; D000818:Animals; D001920:Bradykinin / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D004195:Disease Models, Animal; D007839:Functional Laterality; D019004:Galanin / Q000494:pharmacology / Q000627:therapeutic use / Q000031:analogs & derivatives; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods; D010446:Peptide Fragments / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D044091:Receptor, Galanin, Type 1 / Q000235:genetics / Q000378:metabolism*; D012585:Sciatica / Q000188:drug therapy / Q000473:pathology*
chemical_list: D000700:Analgesics; C000614145:M617 peptide; D010446:Peptide Fragments; D044091:Receptor, Galanin, Type 1; C074069:galanin-(1-13)-bradykinin-(2-9)-amide; D019004:Galanin; D001920:Bradykinin
keywords: AB_2107445; M617; antinociception; galanin; galanin receptor; hindpaw withdrawal latency