Effects of central neuropeptide S in the mouse formalin test.
Neuropeptide S (NPS), a recently discovered bioactive peptide, was reported to regulate arousal, anxiety, locomotion, feeding behaviors, memory, and drug addiction. NPS receptor (NPSR) mRNA was found in several brain regions related to descending control system of pain, including the periaqueductal gray (PAG). Our previous study had shown that NPS could produce antinociception in mice. The present study was designed to evaluate whether NPS may produce antinociceptive effect observed in the mouse formalin test, a model of inflammatory pain. NPS (0.1-100 pmol) administrated intracerebroventricularly (i.c.v.) dose-dependently attenuated both first-phase and second-phase nociceptive behaviors induced by paw formalin injection. NPS (10 pmol, i.c.v.)-elicited antinociceptive effect was counteracted by co-injection with 1000 and 10,000 pmol [D-Val(5)]NPS, which alone induced neither hyperalgesia nor antinociception. The antinociception induced by NPS (10 pmol, i.c.v.) was not affected by naloxone (i.p., 10 mg/kg) and naloxone alone had no effect in the formalin test. In addition, compared to the saline (i.c.v.) treated group, NPS (10 pmol, i.c.v.) treated group increased c-Fos protein expression in nearly all subdivisions of the PAG in the formalin-injected mice. The above results revealed that NPS could produce antinociception in the formalin test through NPSR, which may be involved in the activation of PAG, suggesting that NPS-NPSR system may be a potential target for developing new analgesic drugs.
Peng
Ya-Li
YL
Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, State Key Laboratory of Applied Organic Chemistry, and Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, 222 Tian Shui South Road, Lanzhou 730000, PR China.
Zhang
Jian-Nan
JN
Chang
Min
M
Li
Wei
W
Han
Ren-Wen
RW
Wang
Rui
R
D000700:Analgesics / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009479:Neuropeptides / Q000494:pharmacology / Q000627:therapeutic use; D010146:Pain / Q000188:drug therapy*; D010147:Pain Measurement / Q000187:drug effects*; D010487:Periaqueductal Gray / Q000166:cytology / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism
D000700:Analgesics; C515062:NPSR1 protein, mouse; D009292:Narcotic Antagonists; D009479:Neuropeptides; D016760:Proto-Oncogene Proteins c-fos; D043562:Receptors, G-Protein-Coupled; C539972:neuropeptide S, mouse; D009270:Naloxone