We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Phoneutria nigriventer spider venom activates 5-HT[sub4] receptors in rat-isolated vagus nerve.
- Authors
Costa, Soraia K.P.; Brain, Susan D.; Antunes, Edson; De Nucci, Gilberto; Docherty, Reginald J.
- Abstract
1 The venom of Phoneutria nigriventer spider (PNV) causes intense pain and inflammation following an attack. We have investigated the involvement of capsaicin-sensitive nerve fibres by utilizing an in vitro nerve preparation. Extracellular DC potential recordings were made from the rat-isolated vagus nerve, a preparation that is rich in capsaicin-sensitive, that is, nociceptive, C-fibres. 2 PNV (1-10 μg ml[SUP-1]), capsaicin (0.03-0.3 μM) or 5-hydroxytriptamine (5-HT) (0.3-3μM) induced dose-dependent deplorizations of vagus nerve fibres. Depolarizing responses to capsaicin were blocked by ruth by ruthenium red (RR, 10 μM), but respnoses to PNV were not. Depolarizing responses to PNV or veratridine (50 μM) were inhibited by tetrodotoxin (TTX, 10μM), but those to capsaicin were not. This suggests that capsaicin and PNV depolarize that nerve fibres by distinct mechanisms. 3 Depolarization in response to 5-HT (3 μM) was reduced by the 5-HT[SUB3] receptor antagonists Y25130 (0.5μM) and tropisetron (10nM) or, to a lesser extent, by the 5-HT[SUB4] receptor antagonists RS39604 (1 or 10 μM). Depolarizing responses to PNV were not affected significantly by Y25130 or tropisetron, but were blocked by RS39604. 4 These data show that 5-HT[SUB4] receptors play a significant role in the activation of nociceptive sensory nerve fibres by PNV and suggest that this is of importance in the development of the pain and inflammation associated with bites from the P. nigriventer spider.
- Subjects
SPIDER venom; VAGUS nerve
- Publication
British Journal of Pharmacology, 2003, Vol 139, Issue 1, p59
- ISSN
0007-1188
- Publication type
Article
- DOI
10.1038/sj.bjp.0705240