Histamine release into tracheal lumen and bronchial reactivity. Effect of local allergen administration on histamine release and bronchial reactivity

The correlation between allergen, acetylcholine and histamine-induced bronchoconstriction

A significant correlation between the degree of bronchial reactivity to ACH, Hi and A.E. was found in a series of 23 dogs. An increase in receptors sensitivity responsible for the organic manifestation of allergy must be assumed. This increased receptors sensitivity is an important phenomenon in asthma clinically relevant.

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.

Histamine release into tracheal lumen and bronchial reactivity. Effect of compound 48/80 administered by different routes in various doses on histamine release and bronchial reactivity

The influence of tracheal lavage with compound 48/80 on the bronchial response to challenge with ACH and AE was studied in 24 animals. Furthermore, the effect of i.v. administration of 48/80 was compared to its administration into the tracheal lumen. No increased histamine liberation was detected in the tracheal fluid after lavage with 48/80, nor was an influence on the bronchial response observed. These observations were the same as those described for tracheal lavage with water. The same amounts of this secretagogue induced, after i.v. administration, a high histamine release which correlates significantly with blood pressure decrease.

Histamine release into tracheal lumen and bronchial reactivity. Effect of local histamine administration on histamine release and bronchial reactivity

The influence of tracheal lavage with histamine, and of i.v. administration of histamine on bronchospastic response was studied in 16 dogs. Airway response to acetylcholine inhalation was significantly increased after tracheal lavage with high concentrated histamine solution (1%). No influence on airway response was found after (1) tracheal lavage with lower concentrations of histamine and (2) its i.v. administration. The clinical importance of these manifestations is discussed.