title: Effects of Endokinin A/B and Endokinin C/D on the antinociception of Endomorphin-1 in mice.
abstract: In our previous study, Endokinin A/B (EKA/B, the common C-terminal decapeptide in Endokinin A and Endokinin B) was found to induce analgesic effect at high dose and nociception at low dose, while Endokinin C/D (EKC/D, the common C-terminal duodecapeptide in Endokinin C and Endokinin D) has analgesic effect only. So in this study an attempt was undertaken to investigate the interaction of EKA/B and EKC/D with Endomorphin-1 (EM-1) on antinociceptive effect at supraspinal level. Results showed that the antinociceptive effect of EM-1 was enhanced by high dose of EKA/B and abolished by low dose of EKA/B, while EKC/D could only enhance the analgesic effect. Mechanism studies showed that EKA/B blocked the antinociception of EM-1 by activating neurokinin-1 receptor (NK(1)), whose specific antagonist, SR140333B could fully block EKA/B-induced attenuation on the analgesic response of EM-1. Surprisingly, EKC/D could also block the same EKA/B-induced attenuation. Taken together, the different effects of EKA/B and EKC/D on the antinociception of EM-1 may pave the way for a new strategy on investigating the interaction between tachykinins and opioids on pain modulation.
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, 222 Tianshui South Road, Lanzhou, Gansu 730000, China.
authors.forename: Yinliang
authors.initials: Y
authors.lastname: Yang
authors.forename: Zhongqiu
authors.initials: Z
authors.lastname: Ni
authors.forename: Shouliang
authors.initials: S
authors.lastname: Dong
mesh_terms: D000701:Analgesics, Opioid / Q000378:metabolism / Q000627:therapeutic use*; D000818:Animals; D006801:Humans; D008297:Male; D051379:Mice; D009270:Naloxone / Q000378:metabolism; D009292:Narcotic Antagonists / Q000378:metabolism; D064729:Neurokinin-1 Receptor Antagonists; D009842:Oligopeptides / Q000378:metabolism / Q000627:therapeutic use*; D010146:Pain / Q000188:drug therapy*; D010147:Pain Measurement; D020033:Protein Isoforms / Q000494:pharmacology*; D011498:Protein Precursors / Q000494:pharmacology*; D015320:Tachykinins / Q000494:pharmacology*; D014326:Tropanes / Q000378:metabolism
chemical_list: D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D064729:Neurokinin-1 Receptor Antagonists; D009842:Oligopeptides; D020033:Protein Isoforms; D011498:Protein Precursors; C526005:SR140333B; C423233:Tac4 protein, mouse; D015320:Tachykinins; D014326:Tropanes; C105293:endomorphin 1; D009270:Naloxone