Nebivolol and airway responsiveness in the rabbit

Beta-adrenergic receptor antagonists are currently used as first-line therapy in the treatment of hypertension and angina pectoris, but are contraindicated or used with caution in patients with bronchospastic syndromes. In this study we evaluated in vivo the effects of nebivolol on airway responsiveness compared to atenolol, pindolol, and propranolol. In New Zealand white rabbits total lung resistance (R(L)) and dynamic compliance (Cdyn) were calculated. In acute protocol, the animals were intravenously injected with the beta-blockers at different doses while in the chronic protocol, animals were daily injected for 30 days. Furthermore, the changes induced by beta-blockers (higher doses) in R(L) and Cdyn after a treatment with salbutamol were calculated. In acute treatment, airway responsiveness to histamine was not modified by nebivolol at any dosage, but increased significantly following the exposure to the higher doses of the other beta-blockers. In chronic treatment, the thirty-day exposure to nebivolol, did not modify the airway responsiveness to histamine, whereas the other beta-blockers significantly increased airway responsiveness. Moreover, nebivolol affected the salbutamol-induced relaxation less markedly than other beta-blockers do. These data demonstrate that nebivolol respect the other beta-blockers used in this study, does not significantly affect the airway responsiveness, therefore it could be used in patients with both cardiovascular and bronchial diseases more safely than other beta-blockers drugs.