Influence of capsaicin on the reagibility of the isolated guinea pig trachea.
Capsaicin induced a concentration dependent contraction of isolated guinea pig tracheal spirals but did not reduce the tone of submaximally precontracted preparations neither per se nor after pretreatment with a tachykinin antagonist. The contractile reactions to capsaicin did not differ significantly between tracheal preparations obtained from sensitized and nonsensitized animals. A single application of capsaicin (10(-5) M for 15 min) induced a strong contraction of the preparations followed by complete tachyphylaxis to further applications of capsaicin. Such pretreatment with capsaicin did not influence the reagibility of isolated guinea pig tracheas to acetylcholine added exogenously but reduced the allergic contractions of preparations obtained from actively sensitized animals significantly. It is suggested that neuropeptides (e.g. substance P) might be involved in the allergic bronchoconstriction in vitro.
Schreiber
J
J
Research Institute for Lung Diseases and Tuberculosis, Asthma Department, GDR.
Slapke
J
J
Nieber
K
K
Oehme
P
P
D000818:Animals; D002211:Capsaicin / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D013373:Substance P / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects*
D013373:Substance P; D002211:Capsaicin