Neuropeptide FF and related peptides attenuates warm-, but not cold-water swim stress-induced analgesia in mice.
Neuropeptide FF (NPFF) belongs to a neuropeptide family including two receptors (NPFF(1) and NPFF(2)). NPFF system has been reported to play important roles in pain transmission. The aim of the present study was to investigate the roles of NPFF related peptides and their receptors in swim stress-induced analgesia (SIA). Nociceptive test was performed in mice stressed by forced swimming in water at 15 °C (cold water swimming) or 32 °C (warm water swimming). Warm water swimming produced a naloxone-mediated antinociceptive effect. This warm water swim SIA was dose-dependently antagonized by i.c.v. injection of NPFF and two related peptides (3-30 nmol), NPVF and dNPA, which exhibited the highest selectivities for NPFF(1) and NPFF(2) receptors, respectively. Moreover, the selective NPFF receptor antagonist RF9 (30 nmol) was inactive by itself, but prevented the effects of NPFF and related peptides. Cold-water swimming produced a wilder analgesic effect that was blocked by MK-801, but not naloxone. However, NPFF system failed to modify the cold water swim stress-induced analgesia. These findings demonstrated that NPFF and related peptides attenuated opioid-mediated form of SIA via NPFF receptors in the brain, but not non-opioid swim stress-induced analgesia. These data further support an anti-opioid character of NPFF system.
Key Laboratory of Preclinical Study for New Drugs of Gansu Province, and Institute of Physiology & Psychology, School of Basic Medical Sciences, Lanzhou University, 199 Donggang West Road, Lanzhou 730000, PR China.
Ning
N
Li
Zheng-lan
ZL
Han
Quan
Q
Fang
Zi-long
ZL
Wang
Hong-zhu
HZ
Tang
Hui
H
Ren
Rui
R
Wang
D000218:Adamantane / Q000008:administration & dosage / Q000031:analogs & derivatives; D000698:Analgesia; D000704:Analysis of Variance; D000818:Animals; D003080:Cold Temperature; D004151:Dipeptides / Q000008:administration & dosage; D016291:Dizocilpine Maleate / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D006358:Hot Temperature; D007270:Injections, Intra-Articular; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009270:Naloxone / Q000008:administration & dosage; D009292:Narcotic Antagonists / Q000008:administration & dosage; D009479:Neuropeptides / Q000008:administration & dosage; D018696:Neuroprotective Agents / Q000008:administration & dosage; D009842:Oligopeptides / Q000008:administration & dosage*; D013315:Stress, Psychological / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology*; D013550:Swimming / Q000523:psychology
D004151:Dipeptides; D009292:Narcotic Antagonists; D009479:Neuropeptides; D018696:Neuroprotective Agents; D009842:Oligopeptides; C508361:adamantylcarbonyl-arginyl-phenylalaninamide; C503959:neuropeptide VF; D009270:Naloxone; D016291:Dizocilpine Maleate; C053651:phenylalanyl-leucyl-phenylalanyl-glutaminyl-prolyl-glutaminyl-arginyl-phenylalaninamide; D000218:Adamantane