Local release of histamine, prostaglandin F2 alpha and thromboxane B2 into the tracheal lumen and its influence on airways reactivity.

The influence of tracheal lavage with ascaris extract (AE) on airway response to acetylcholine (ACH) and histamine (Hi) was investigated in a series of 24 dogs. AE administered to a restricted area of the trachea resulted in a release of various mediators such as Hi, prostaglandin F2 alpha (PGF2 alpha, measured as the metabolite 15-keto-13, 14-dihydro-PGF2 alpha) and thromboxane B2 (TXB2) into the tracheal lumen. This differed from H2O administration which resulted in no increased release of these mediators. The relatively small concentrations of these substances measured in arterial plasma argue for the role of these mediators on a local basis. On the other hand, tracheal lavage with allergen induced changes in airway response to ACH and Hi aerosols which was not observed after tracheal lavage with water. An interaction between this allergen-induced mediator release into the trachea and peripheral airways reactivity could be demonstrated.