Effect of intranasal administration of CV-11974, a type 1 angiotensin II receptor antagonist, on airway hyperresponsiveness and airway inflammation induced by antigen inhalation in guinea pigs.

Background: Angiotensin II is a putative mediator in asthma, but the effect of topical administration of type 1 angiotensin II (AT1) receptor antagonists on allergic airway reactions is not known. Objective: To investigate the effect of intranasal administration of CV-11974, an AT1 receptor antagonist, and of PD123319, a type 2 angiotensin II (AT2) receptor antagonist, on antigen-induced airway reactions in guinea pigs. Methods: Thirty minutes after intranasal topical administration of CV-11974 (0.1 or 1.0 mg/ml) or PD123319 (10 mg/ml) into the airways, the animals were given an antigen challenge. Airway hyperresponsiveness and bronchoalveolar lavage fluid were analyzed 24 h after the antigen challenge. Results: Although these compounds did not inhibit antigen-induced early-phase bronchoconstriction or late-phase airway eosinophilia, intranasal administration of CV-11974 (but not PD123319) inhibited antigen-induced airway hyperresponsiveness in a dose-dependent manner 24 h after the antigen challenge. Conclusion: Intranasal administration of an AT1 receptor antagonist reduces antigen-induced airway hyperresponsiveness.