Effects of Freund's complete adjuvant and ovalbumin sensitization on the pharmacological reactivity of isolated guinea-pig trachea.

Tracheal strips were obtained from guinea-pigs injected with ovalbumin alone, ovalbumin incorporated into Freund's complete adjuvant (FCA), or FCA alone. There was no difference (P greater than 0.05) in amplitude of ovalbumin-induced contractile responses in tracheas from antigen sensitized and antigen + FCA sensitized animals. Although partial contraction of the muscle with carbachol (ED50) was unaffected by the various treatments, the relaxation responses to isoprenaline, histamine (H2-stimulation) and theophylline were impaired in the group receiving the ovalbumin + FCA sensitization regimen. These results are suggestive of an abnormal response associated with a defective cAMP system in this group.