Involvement of capsaicin-sensitive afferent nerve fibres in serotonin-induced plasma extravasation and vasodilatation in rat skin.
We have investigated the ability of serotonin (5-HT) to induce an inflammatory reaction manifested as plasma extravasation and vasodilatation responses in a blister model in the rat hind footpad. The involvement of unmyelinated sensory fibres in these responses was investigated using capsaicin pretreated rats. 5-HT (0.1-10 microM), when perfused over the blister base, induced both plasma extravasation and vasodilatation responses in a dose-dependent manner. Both the plasma extravasation and the vasodilatation responses were maintained throughout a 30 min stimulation period. Neonatal capsaicin treatment resulted in a 78% and 56% reduction in the plasma extravasation and vasodilatation responses, respectively. The present results provide evidence for the involvement of capsaicin-sensitive sensory nerves in 5-HT-mediated plasma extravasation and vasodilatation responses in the rat.
Khalil
Z
Z
National Research Institute of Gerontology and Geriatric Medicine, Mount Royal Hospital, Melbourne, Australia.
Helme
R D
RD
D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000494:pharmacology*; D007249:Inflammation / Q000139:chemically induced* / Q000503:physiopathology; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000494:pharmacology*; D012867:Skin / Q000098:blood supply / Q000294:innervation; D014664:Vasodilation / Q000187:drug effects*
D012701:Serotonin; D002211:Capsaicin