The obligatory role of calcium in the development of antigen-induced airway hyperreactivity to cold provocation in the rat isolated trachea.
The effect of antigen challenge on cold provocation (30-10 degrees C) in isolated tracheal segments from control (normal) and ovalbumin-sensitized rats was studied. Sensitization alone or acute cold provocation (10 degrees C) alone was not sufficient to cause contraction of tracheal smooth muscle preparation. Following recovery from antigen-induced responses (Schultz-Dale phenomenon) in sensitized rat segments, cold provocation induced strong contractile responses. Both the antigen-induced contractions and the subsequent development of airway hyperreactivity to cold were dependent on extracellular Ca2+ and inhibited by verapamil. The data in this study indicate that extracellular Ca2+ plays an obligatory role in the mediation of antigen-induced contractile responses as well as the subsequent development of hyperreactivity to cold provocation in rat tracheal smooth muscle.
D000818:Animals; D000941:Antigens / Q000276:immunology; D002118:Calcium / Q000502:physiology*; D003080:Cold Temperature; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D010047:Ovalbumin / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains; D012130:Respiratory Hypersensitivity / Q000175:diagnosis / Q000503:physiopathology*; D014132:Trachea / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology
D000941:Antigens; D010047:Ovalbumin; D014700:Verapamil; D002118:Calcium