title: Role of voltage-gated cation channels and axon reflexes in the release of sensory neuropeptides by capsaicin from isolated rat trachea.
abstract: In order to reveal the role of axon reflexes and sensory receptors in sensory neuropeptide release in response to capsaicin, liberation of substance P, calcitonin gene-related peptide and somatostatin from isolated rat tracheae was investigated in the presence of voltage-sensitive Na(+) and Ca(2+) channel blocking agents. Neuropeptide release induced by capsaicin (10 nM) remained unchanged in the presence of 25 mM lidocaine, 1 microM tetrodotoxin or the N-type Ca(2+) channel inhibitor, omega-conotoxin GVIA (100-300 nM). Peptide release by 100 pulses of 2 Hz field stimulation was prevented by lidocaine or tetrodotoxin. Omega-agatoxin TK (250 nM) significantly inhibited and Cd(2+) (200 microM) prevented capsaicin-induced neuropeptide release. These results suggest that chemical stimulation-induced neuropeptide release does not involve activation of fast Na(+) channels or N- and P-type voltage-dependent Ca(2+) channels, but contribution of Q-type Ca(2+) channels is possible. Sensory neuropeptides are released by capsaicin from sensory receptors without axon reflexes.
authors.affiliation: Neuropharmacology Research Group of the Hungarian Academy of Sciences, Pécs, Hungary.
authors.forename: József
authors.initials: J
authors.lastname: Németh
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Helyes
authors.forename: Gábor
authors.initials: G
authors.lastname: Oroszi
authors.forename: Balázs
authors.initials: B
authors.lastname: Jakab
authors.forename: Erika
authors.initials: E
authors.lastname: Pintér
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Szilvássy
authors.forename: János
authors.initials: J
authors.lastname: Szolcsányi
mesh_terms: D060848:Agatoxins; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000187:drug effects* / Q000502:physiology; D002104:Cadmium / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D002211:Capsaicin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D009479:Neuropeptides / Q000378:metabolism*; D051381:Rats; D012018:Reflex / Q000187:drug effects; D015222:Sodium Channels / Q000187:drug effects* / Q000502:physiology; D013004:Somatostatin / Q000378:metabolism; D013111:Spider Venoms / Q000494:pharmacology; D013373:Substance P / Q000378:metabolism; D013779:Tetrodotoxin / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D020866:omega-Conotoxin GVIA / Q000494:pharmacology
chemical_list: D060848:Agatoxins; D000779:Anesthetics, Local; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D009479:Neuropeptides; D015222:Sodium Channels; D013111:Spider Venoms; C083855:omega-agatoxin-Aa4b; D002104:Cadmium; D013373:Substance P; D013779:Tetrodotoxin; D013004:Somatostatin; D020866:omega-Conotoxin GVIA; D008012:Lidocaine; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin