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.