Objective: To investigate the expressions of endothelin-1(ET-1) and endothelin converting enzyme (ECE) mRNA in bronchial mucosal biopsis from asthmatics, and the effect of inhaled-corticosteroids on the expressions of ET-1 and ECE genes.
Method: The expressions of ET-1 and ECEmRNA in bronchial mucosal tissue were evaluated by reverse transcription DNA polymerase chain reaction (RT-PCR); With fibro bronchoscopy, the naked-eye inflammatory severity and inflammatory score of bronchial mucoses were recorded.
Result: (1) The expression level of ET-1 mRNA was 0.86 +/- 0.06 in non-steroids-treated group and 0.14 +/- 0.06 in control non-asthmatic group. The expression of ECE mRNA in non-steroid group was 0.31 +/- 0.04, and 0.30 +/- 0.05 in control group, P = 0.238. (2) The ET-1 and ECE mRNA expressions were 0.22 +/- 0.01 and 0.16 +/- 0.01 respectively in steroid treated group. (3) The naked-eye bronchial mucosal inflammatory score was 6.0 +/- 1.9 in non-steroids treated group, moreover, the expression of ET-1 mRNA was positively correlated with the score (r = 0.78, P < 0.05).
Conclusion: There was markedly higher ET-1 mRNA expression in the bronchial mucosa in asthmatics, but the ECE mRNA expression was unchanged significantly; Inhaled corticosteroids obviously inhibited both ET-1 mRNA and ECE mRNA expressions in bronchial mucosa, which may be one of the anti-inflammatory mechanisms of inhaled-corticosteroid in management of bronchial asthma.