Anti-hyperalgesic effects of anti-serotonergic compounds on serotonin- and capsaicin-evoked thermal hyperalgesia in the rat

Published by Elsevier Ltd..

The peripheral serotonergic system has been implicated in the modulation of an array of pain states, from migraine to fibromyalgia; however, the mechanism by which serotonin (5HT) induces pain is unclear. Peripherally released 5HT induces thermal hyperalgesia, possibly via modulation of the transient receptor potential V1 (TRPV1) channel, which is gated by various noxious stimuli, including capsaicin. We previously reported in vitro that 5HT increases calcium accumulation in the capsaicin-sensitive population of sensory neurons with a corresponding increase in proinflammatory neuropeptide release, and both are antagonized by pretreatment with 5HT(2A) and 5HT(3) antagonists, as well as the anti-migraine drug sumatriptan. In the current study, we extended these findings in vivo using the rat hind paw thermal assay to test the hypothesis that peripheral 5HT enhances TRPV1-evoked thermal hyperalgesia that can be attenuated with 5HT(2A) and 5HT(3) receptor antagonists, as well as sumatriptan. Thermal hyperalgesia and edema were established by 5HT injection (0.1-10 nmol/100 μl) into the rat hind paw, and the latency to paw withdrawal (PWL) from noxious heat was determined. Rats were then pretreated with either 5HT before capsaicin (3 nmol/10 μl), the 5HT(2A) receptor antagonist ketanserin or the 5HT(3) receptor antagonist granisetron (0.0001-0.1 nmol/100 μl) before 5HT and/or capsaicin, or the 5HT(1B/1D) receptor agonist sumatriptan (0.01-1 nmol/100 μl) before capsaicin, and PWL was determined. We report that 5HT pretreatment enhances TRPV1-evoked thermal hyperalgesia, which is attenuated with local pretreatment with ketanserin, granisetron, or sumatriptan. We also report that peripheral 5HT induced a similar magnitude of thermal hyperalgesia in male and female rats. Overall, our results provide in vivo evidence supporting an enhancing role of 5HT on TRPV1-evoked thermal hyperalgesia, which can be attenuated by peripheral serotonergic intervention.

Medienart:

E-Artikel

Erscheinungsjahr:

2012

Erschienen:

2012

Enthalten in:

Zur Gesamtaufnahme - volume:203

Enthalten in:

Neuroscience - 203(2012) vom: 17. Feb., Seite 207-15

Sprache:

Englisch

Beteiligte Personen:

Loyd, D R [VerfasserIn]
Chen, P B [VerfasserIn]
Hargreaves, K M [VerfasserIn]

Links:

Volltext

Themen:

333DO1RDJY
8R78F6L9VO
97F9DE4CT4
Capsaicin
Journal Article
Ketanserin
Research Support, N.I.H., Extramural
S07O44R1ZM
Serotonin
Serotonin Antagonists
Serotonin Receptor Agonists
Sumatriptan

Anmerkungen:

Date Completed 19.07.2012

Date Revised 21.10.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.neuroscience.2011.12.019

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM214228312