Pharmacological study of chicken airway smooth muscle

Isolated chicken bronchus contracts to carbachol, PGF2alpha, histamine, 5-HT, bradykinin and phenylephrine. The bronchial strips from the horse plasma sensitized domestic fowl contracted to specific sensitizing antigen in vitro (Schultz-Dale anaphylactic reaction) and were 5 to 10 fold more reactive to PGF2alpha, histamine and 5-HT compared with the bronchi from normal chickens. Second antigen challenge was inactive or produced a weak response (desensitization). Allowing the bronchi to rest for 1 h resulted in partial recovery of anaphylactic response. Bronchi which had partially contracted submaximally to carbachol, antigen or PGF2alpha, relaxed to isoprenaline, adrenaline and PGE1 and E2.