[Endothelin concentration in sera of patients with atopic bronchial asthma]

Endothelin-1 (ET-1) is an effective vasoconstrictor and has bronchoconstricting property. Recent findings in vivo and in vitro indicate the influence of ET-1 on bronchial smooth muscle tone. ET-1 concentration was detected in BAL-Fluid in patients with bronchial asthma. Previous studies indicated an increase in ET-1 serum concentrations in the course of exacerbation of asthma. The purpose of our study was to compare ET-1 concentrations in sera of asthmatics during the asymptomatic period and after metacholine provocation. The study was performed in a group of 16 patients with mild bronchial asthma and in 11 healthy subjects. ET-1 concentrations in sera were evaluated by Elisa method (kit R&D USA). Bronchial provocation with metacholine was performed in asthmatics using Bronchoscreen. The result was considered as positive with FEV1, decrease of at least 20%. Airway responsiveness to metacholine was expressed as PC20. The results were analyzed statistically by means of the Student's test. The baseline ET-1 levels in sera of healthy donors were lower then in asthmatics group (x1' = 4.72 +/- 1.01, x1 = 11.53 +/- 3.68 pg/ml, p < 0.001). We found a statistically significant increase of ET1-1 concentration in sera after inhalation of metacholine (x1 = 11.55 +/- 3.68; x2 = 24.08 +/- 4.09 pg/ml, p < 0.001). The results indicate that ET-1 may play a role in bronchospasm in asthmatics.