Endothelin-1 (ET-l) is a potent bronchoconstrictor which may have a role in the pathogenesis of asthma. To clarify the interrelation between ET-1 and bronchial asthma, the concentrations of ET-1 in plasma and BAL fluid were measured (by ELISA technique) in (10) healthy subjects, (10) patients with atopic asthma treated with bronchodilators alone (Group I), and (10) patients with atopic asthma treated with inhaled and / or oral corticosteroicls (Croup II). Pulmonary functions (FEVI% predicted and FEF25-75% predicated) and the provocation concentrations of methacholine required to reduce FEVI by 20% of the prechallenge baseline (PD20) were also measured. There was no significant difference in the plasma ET-I level among either the control group and group 1(15.95 ± 6.5 pg/ml versus 17.84 ± 7.8 pg/m1) and group 11 (15.95±6.5 pg / ml versus 16.75 ± 6.7 pg/ ml) or group I and 11 (17.84 ± 7.8 versus16.75-6.7 pg/ m1). There was a significant increase in BAL fluid ET-I levels in both the non steroid treated patients with asthma (Group 1) and the steroid treated patients (Group II) compared with the normal subjects (20.94 + 3.96 pg/ml versus 15.61 -337 pg/ ml) and (16.03 - 3.5 pg/ ml versus 15.61 + 3.37 pg /m1) respectively. There was statistically significant difference in BAL ET-I level between Group II and grup I indicating that ET-1 BAL level may be modulated by corticosteroid therapy. In group I and 11 there was a significant negative correlation between the BAL ET-1 concentrations and ventilatory functions (96 predicted FEVI and FEF25-759&. No correlation between BAL fluid ET-I concentrations and bronchial reactivity or plasma |
