Effect of thromboxane A2-receptor antagonist on bradykinin-induced bronchoconstriction in asthma.
J Appl Physiol (1985)
; 80(6): 1973-7, 1996 Jun.
Article
em En
| MEDLINE
| ID: mdl-8806903
ABSTRACT
The role of the thromboxane A2 (TxA2) receptor in bradykinin-induced bronchial responses was investigated in this study by using a selective and potent TxA2-receptor antagonist BAY u 3405. Eleven asthmatic subjects were randomized to receive 50 mg of BAY u 3405 or matched placebo in a crossover and double-blind fashion. Ninety minutes after dosing, serum was taken for drug assay, and subjects underwent provocation with bradykinin or prostaglandin D2 (PGD2) to determine bronchial responsiveness [provocative concentration of agonist required to produce a 20% fall in forced expiratory volume in 1 s from the postdiluent baseline (PC20)]. Pretreatment with BAY u 3405 caused a twofold doubling-dilution reduction in bronchial reactivity to PGD2; the geometric mean PC20 values were 0.132 (0.015-0.871) and 0.034 (0.008-0.095) mg/ml, respectively, for active and placebo days (P = 0.001). There was, however, no significant difference in PC20 values for bradykinin between active and placebo treatment days. We have demonstrated that BAY u 3405 caused a significant inhibition of bronchconstriction induced by inhaled PGD2 but had no influence on bronchial responsiveness to inhaled bradykinin. This study suggests therefore that TxA2 receptors do not play a role in bradykinin-induced bronchoconstriction in asthma.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Asma
/
Sulfonamidas
/
Bradicinina
/
Carbazóis
/
Inibidores da Agregação Plaquetária
/
Broncoconstrição
/
Receptores de Tromboxanos
Tipo de estudo:
Clinical_trials
Limite:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Ano de publicação:
1996
Tipo de documento:
Article