Beta-adrenergic receptor antagonists are currently used as first-line thera
py in the treatment of hypertension and angina pectoris, but are contraindi
cated or used with caution in patients with bronchospastic syndromes. In th
is study we evaluated in vivo the effects of nebivolol on airway responsive
ness compared to atenolol, pindolol, and propranolol. In New Zealand white
rabbits total lung resistance (R-L) and dynamic compliance (C-dyn) were cal
culated. In acute protocol, the animals were intravenously injected with th
e 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 C-dyn 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 follo
wing the exposure to the higher doses of the other beta -blockers. In chron
ic treatment, the thirty-day exposure to nebivolol did not modify the airwa
y responsiveness to histamine, whereas the other beta -blockers significant
ly increased airway responsiveness. Moreover, nebivolol affected the salbut
amol-induced relaxation less markedly than other beta -blockers do. These d
ata demonstrate that nebivolol respect the other beta -blockers used in thi
s study, does not significantly affect the airway responsiveness, therefore
it could be used in patients with both cardiovascular and bronchial diseas
es more safely than other beta -blockers drugs. (C) 2001 Elsevier Science I
nc. All rights reserved.