Capsaicin and anaphylactic reactions in the guinea-pig airways.
Further evidence is reported on the influence exerted by capsaicin on the anaphylactic reaction evoked in actively sensitized guinea-pigs. In Herxheimer microshock induced by ovalbumin aerosol, pretreatment of animals with 100 micrograms/kg i.p. capsaicin prolonged the preconvulsion time when the drug was administered 3 h before antigen challenge. In contrast, the same dose of capsaicin injected 30 min before aerosol caused a shortening of latency of the respiratory symptomatology. The influence of the drug is no longer evident after 24 h. In "in vitro" experiments desensitization to capsaicin of tracheal preparations caused a reduction of histamine and SRS-A released during antigen challenge, in comparison to controls. Moreover, anaphylactic histamine release was increased in preparations perfused with 10(-8) M substance P. In conclusion, our findings confirm that neuropeptides may be involved in the pathogenesis of asthma by affecting release of mediators.
Dipartimento di Farmacologia Preclinica e Clinica, Universitá di Firenze, Italy.
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G
Gentilini
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Franchi-Micheli
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M
Ciuffi
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D
Bindi
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L
Zilletti
D000707:Anaphylaxis / Q000503:physiopathology*; D000818:Animals; D001249:Asthma / Q000378:metabolism / Q000503:physiopathology; D002211:Capsaicin / Q000494:pharmacology*; D006168:Guinea Pigs; D006636:Histamine Release / Q000187:drug effects; D007082:Ileum / Q000187:drug effects; D008297:Male; D010047:Ovalbumin / Q000276:immunology; D012137:Respiratory System / Q000503:physiopathology*; D014132:Trachea / Q000187:drug effects
D010047:Ovalbumin; D002211:Capsaicin