title: Serotonin receptor 5-HT2B mediates serotonin-induced mechanical hyperalgesia.
abstract: Serotonin [5-hydroxytryptamine (5-HT)] released from mast cells or platelets in peripheral tissues is one of the important inflammatory mediators in pain and hyperalgesia. The involvement of 5-HT in pain is complex because it could inhibit or facilitate nociceptive transmission, reflecting the presence of multiple 5-HT subtype receptors on peripheral and central nociceptors. The present study aimed to investigate the involvement of 5-HT(2B) in 5-HT-induced pain and whether the subtype exists in dorsal root ganglion (DRG) neurons. Injecting the 5-HT or 5-HT(2) agonist in hindpaws of mice induced significant hyperalgesia to mechanical stimuli, which was inhibited by the 5-HT(2B/2C) antagonist but not by 5-HT(1A), 5-HT(2A), or 5-HT(3A) antagonists. Therefore, 5-HT(2B) or 5-HT(2C) may be involved in 5-HT-induced mechanical hyperalgesia. The 5-HT(2B/2C) antagonist also blocked 5-HT-induced transient [Ca(2+)] signaling in DRG neurons. All subtypes of 5-HT receptors except 5-HT(2C) and 5-HT(6) are present in DRGs. In situ hybridization also demonstrated 5-HT(2B) mainly expressed in small- to medium-diameter DRG neurons that respond to pain. Likely, 5-HT(2B) mediates 5-HT-induced mechanical hyperalgesia in mice.
authors.affiliation: Department of Life Sciences, National Central University, Jhongli 32054, Taiwan.
authors.forename: Shih-Yuan
authors.initials: SY
authors.lastname: Lin
authors.forename: Wei-Jen
authors.initials: WJ
authors.lastname: Chang
authors.forename: Chih-Shin
authors.initials: CS
authors.lastname: Lin
authors.forename: Chun-Ying
authors.initials: CY
authors.lastname: Huang
authors.forename: Hui-Fang
authors.initials: HF
authors.lastname: Wang
authors.forename: Wei-Hsin
authors.initials: WH
authors.lastname: Sun
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects; D002460:Cell Line; D005727:Ganglia, Spinal / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D006930:Hyperalgesia / Q000503:physiopathology*; D007211:Indoles / Q000494:pharmacology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009474:Neurons / Q000378:metabolism; D009619:Nociceptors / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D044403:Receptor, Serotonin, 5-HT2B / Q000502:physiology*; D044405:Receptor, Serotonin, 5-HT2C / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology*; D058830:Serotonin 5-HT2 Receptor Antagonists / Q000494:pharmacology; D014110:Touch
chemical_list: D007211:Indoles; D011725:Pyridines; D044403:Receptor, Serotonin, 5-HT2B; D044405:Receptor, Serotonin, 5-HT2C; D058830:Serotonin 5-HT2 Receptor Antagonists; D012701:Serotonin; C094868:SB 206553