FAILURE OF AEROSOLIZED ENDOTHELIN (ET-1) TO INDUCE BRONCHIAL HYPERREACTIVITY IN THE GUINEA-PIG

Summary— Aerosol administration of endothelin (ET‐1) has been shown to provoke a potent bronchoconstriction in the guinea pig. We investigated whether or not, aerosolized ET‐1 induces a bronchial hyperreactivity in the guinea pig. Aerosolized ET‐1 (10 μg/ml for 60 min) did not alter the dose‐response curve, established by successive aerosol administration of acetylcholine (ACh) 3–4 h and 18–24 h after challenge with the peptide. In a second protocol, aerosolized ET‐1 (10 μg/ml for 3 min) induced, in anaesthetized guinea pigs a bronchopulmonary response but did not alter the dose‐response curve to aerosolized ACh established 30 min after the challenge. These results suggest that ET‐1 may participate to the early, but not the late alteration of the bronchopulmonary tone observed during pathophysiological conditions. 1990 Société Française de Pharmacologie et de Thérapeutique