[Allergen-induced airway obstruction and histamine concentration in arterial and venous plasma. First communication (author's transl)].

In 19 dogs sensitized against Ascaris suum extract we measured dynamic elastance, arterial plasma histamine concentration, pressure in the A. femoralis, and arterial blood gases. In six dogs the venous plasma histamine concentration was also analyzed. Ascaris extract (A.E.) inhalation increased both the arterial and the venous plasma histamine concentration significantly. The venous concentration was 61% of that detected in the arterial blood. At the same arterial plasma histamine level a large variety of dynamic elastance was measured which shows great individual differences in the sensitivity of the bronchoconstrictive system. This histamine released by the bronchopulmonary system works mostly via reflex bronchoconstriction. There was significant correlation between dynamic elastance and arterial oxygen pressure as well as between arterial plasma histamine concentration and systemic blood pressure.