Objective To explore the role of endothelin (ET) in the pathogenesis of exercise induced asthma (EIA), we investigated the effects of ET B receptor antagonists, ET 1 11 21 fragment and N cis 2,6 dimethylp...Objective To explore the role of endothelin (ET) in the pathogenesis of exercise induced asthma (EIA), we investigated the effects of ET B receptor antagonists, ET 1 11 21 fragment and N cis 2,6 dimethylpi^peridinocardonyl L γ methylleucyl D 1 methoxycarbonyl tryptophanyl D norleucine (BQ788) on broncho^constriction elicited by isocapnic hyperpnea in guinea pigs Methods Eighteen pathogen free Hartley guinea pigs were randomly divided into three groups A: normal saline (NS) inhalation control group (n=6), B: BQ788 group (n=6), and C: ET 1 11 21 fragment group (n=6) Guinea pigs were anesthetized with pentobarbital sodium After measuring the basal value of lung resistance (R L) and dynamic compliance of the respiratory system (Cdyn), NS (0 96?ml), BQ788 (9?nmol) and ET 1 11 21 fragment (9?nmol) were inhaled A rodent respirator with a dry 5%CO 2-95%O 2 mixture at room temperature provided mechanical ventilation (V T 8?ml/animal, 100 breaths/min) for 5?min R L and Cdyn of the 3 groups were measured again after isocapnic hyperpnea challenge Results In the control group, isocapnic hyperpnea of dry gas elicited a marked increase in R L and decrease in Cdyn R L and Cdyn of the guinea pigs from BQ788 group and ET 1 11 21 fragment group did not change significantly Conclusion It was demonstrated that selective ET B receptor antagonists, ET 1 11 21 fragment and BQ788, inhibited the bronchoconstriction induced by isocapnic hyperpnea in guinea pigs The data showed that ETs are potent constrictors of guinea pig airway smooth muscle via a direct effect on ET receptors It was suggested that ET receptor antagonists, especially ET B receptor antagonist, might be beneficial in preventing EIA展开更多
文摘Objective To explore the role of endothelin (ET) in the pathogenesis of exercise induced asthma (EIA), we investigated the effects of ET B receptor antagonists, ET 1 11 21 fragment and N cis 2,6 dimethylpi^peridinocardonyl L γ methylleucyl D 1 methoxycarbonyl tryptophanyl D norleucine (BQ788) on broncho^constriction elicited by isocapnic hyperpnea in guinea pigs Methods Eighteen pathogen free Hartley guinea pigs were randomly divided into three groups A: normal saline (NS) inhalation control group (n=6), B: BQ788 group (n=6), and C: ET 1 11 21 fragment group (n=6) Guinea pigs were anesthetized with pentobarbital sodium After measuring the basal value of lung resistance (R L) and dynamic compliance of the respiratory system (Cdyn), NS (0 96?ml), BQ788 (9?nmol) and ET 1 11 21 fragment (9?nmol) were inhaled A rodent respirator with a dry 5%CO 2-95%O 2 mixture at room temperature provided mechanical ventilation (V T 8?ml/animal, 100 breaths/min) for 5?min R L and Cdyn of the 3 groups were measured again after isocapnic hyperpnea challenge Results In the control group, isocapnic hyperpnea of dry gas elicited a marked increase in R L and decrease in Cdyn R L and Cdyn of the guinea pigs from BQ788 group and ET 1 11 21 fragment group did not change significantly Conclusion It was demonstrated that selective ET B receptor antagonists, ET 1 11 21 fragment and BQ788, inhibited the bronchoconstriction induced by isocapnic hyperpnea in guinea pigs The data showed that ETs are potent constrictors of guinea pig airway smooth muscle via a direct effect on ET receptors It was suggested that ET receptor antagonists, especially ET B receptor antagonist, might be beneficial in preventing EIA
